WO2013039753A1

WO2013039753A1 - Methods for operating a multi-use energy management and conversion system for electric vehicle charging

Info

Publication number: WO2013039753A1
Application number: PCT/US2012/053858
Authority: WO
Inventors: Taras KUCENIUK; Michael BISSONETTE; Omourtag A. Velev; Eric AAGAARD
Original assignee: Aerovironment Inc
Current assignee: Aerovironment Inc
Priority date: 2011-09-16
Filing date: 2012-09-06
Publication date: 2013-03-21
Anticipated expiration: 2014-03-16

Abstract

In an energy management and conversion system for charging an electric vehicle, plural energy sources are coupled to a DC bus through respective converters, and respective voltage set points are provided for the respective converters, each converter controlling flow of energy between the DC bus and the respective energy source by determining whether the voltage of the DC bus is less than the respective voltage set point.

Description

METHODS FOR OPERATING A MULTI-USE ENERGY MANAGEMENT AND CONVERSION SYSTEM FOR ELECTRIC VEHICLE CHARGING

CROSS-REFERENCE TO RELATED APPLICATIONS

[13 This application claims priority of U.S.

Provisional Application Serial No. 61/535,783 filed

September 16, 2011 entitled METHODS FOR OPERATING A

MULTI-USE ENERGY MANAGEMENT CONVERSION SYSTEM FOR

ELECTRIC VEHICLE CHARGING by Taras Kuceniuk, et al.

TECHNICAL EIELD

[2] The present invention in its several exubodiraenfcs pertains to systems and methods of managing electric energy flow or power among different electric energy sources, for charging an electric vehicle and/or

delivering power to one of the energy sources from one or more of the other energy sources.

BACKGROUND

[3J Electric vehicles offer a cleaner and potentially cheaper alternative to conventional fuel-powered

vehicles. A typical electric vehicle (EV) has an

electric motor coupled to the vehicle wheels and a rechargeable battery pack for powering the electric motor. The battery pack may be beneficially recharged at night (tor example) when the electric vehicle is not in use and when electricity is generally more available and less expensive. For this purpose, the electric vehicle further includes an on-board charging system that can be plugged into a household utility outlet in the

residential garage or car port where the electric vehicle is parked.

[43 After a full day's use, it may be necessary to recharge the vehicle's batter pack for several or many hours, depending upon the charging capacity of the onboard charging system. This capacity is limited in order to reduce the size and weight of the on-board charging syste , so as to reduce the weight and enhance the performance of the electric vehicle. Moreover, the charging rate is limited by the power rating of the household utility outlet. Such limitations have the undesirable effect of increasing the araount of time required to recharge the batter pack. Another problem is that the cost of recharging the batter pack is dictated by the rate schedule of the local electric utility supplier, and can be a function of the time of day, nightti e power being generally less expensive and daytime peak demand power being generally more expensive.

SUMMARY OF THE IHVEK IOK

[53 In one embodiment, a method is provided for managing electrical energy in a system for charging an electric vehicle (EV) having an EV battery . The method comprises :

coupling a direct current bus to plural energy sources and to a system port that is connect ble to an EV charging port of the electric vehicle, the plural energy sources comprising one or more energy sources having zero energy cost and one or more energy sources having nonzero energy costs;

connecting the EV charging port to the system port;

receiving a command to charge the EV battery to a specified recharge level by a specified time;

sensing the energy levels of the energy sources and of the EV battery and sensing the present voltage of the direct current bus;

determining an amount of required energy needed for the SV battery to reach the specified recharge level;

establishing respective priorities for respective ones of the energy sources according to selected attributes of the energy sources;

establishing discharge voltage set points for respective ones of the energy sources as a function of the respective priorities; and

comparing the present vol tage of the direct current bus with each one of the discharge voltage set points, and permitting discharge of the corresponding energy source to the direct current bus if the direct current bus voltage is less than the corresponding one discharge voltage set point.

[63 In one aspect, the attributes comprise cost of energy of each energy source and energy available from each energy source. If available energy of a combination of the energy sources having zero energy cost is adequate to meet the required energy, the method further comprises permitting discharge from the combination of energy sources having zero energy cost. [73 In another aspect, the establishing discharge voltage set points comprises establishing discharge voltage set points of energy sources having non-zero energy costs in inverse relation to their energy costs. If available energy of a combination of the energy sources having zero energy cost is not adequate to furnish the additional energy, discharging respective ones of the energ sources having non-zero energy costs to the direct: current bus whenever the voltage of the direct current bus is less than the corresponding

discharge voltage set point.

[8] In one embodiment , the energy sources having zero energy cost comprise at least one of a solar cell array and a wind generator, and the energy sources having nonzero energy costs comprise at least one of a utility grid and a local energy storage unit. If (a) available energy of a coTibinat ion of the energy sources having zero energy cost is not adequate to furnish the required energy, and (b) energy cost of energy stored in the local energy storage unit is less than energy cost of the utility grid, then the method further comprises enabling

discharge of the local energy storage unit to the direct current bus while preventing energy flow from the utility grid to the direct current bus.

[9]: if (A) cost of energy of the utility grid is less than cost of energy stored in the local energy storage unit, or (B) energy from the local energy storage unit is not adequate to furnish the required energy, then the method further comprises (C) enabling a. constant

discharge of the local energy storage device to the direct current bus and enabling energy flow from the utility grid to the direct current bus only during time periods in which utility grid energy cost is below a cost threshold. Further, if energy cost of the local energy storage uni is ess than energy cost of the utility grid, the method further comprises adjusting the

discharge voltage set point for the local energy storage unit to a value higher than a discharge voltage set point for the utility grid before performing the enabling step of (C) .

[10] On the other hand, if energy cost of the local energy storage unit is not less than energy cost of the utility grid, the method comprises adjusting the

discharge voltage set point for the local energy storage unit to be equal to a discharge voltage set point for the utility grid, before performing the enabling step of (C) ,

[11] The method, further comprises searching for a value for the cost threshold at which the energy cost of the grid is below the cost threshold for a sufficient amount of time to obtain the required energy from a combination of the energy sources. Searching for a value for the cost threshold comprises:

determining a required amount of time needed for the utility grid to furnish sufficient energy so that a combination of energy sources including the utility grid can furnish the required energy;

initializing the cost threshold to equal the minimum energy cost occurring between the present time and the specified time; from a profile of utility grid energy costs,, ascertaining the net amount of time that the utility grid energy costs are less than a current value of the cost threshold;

if the net amount of time exceeds the required amount of time, fixing the threshold cost at. is current value;

if the net amount of time does not exceed the required amount of t me, incrementing the current value of the cost threshold and then repeating the ascertaining step and one of the fixing or incrementing steps.

112 J The method may further comprise, prior to

receiving the command, maintaining the EV battery at a long term storage charge level that is in a range of 40%- 65% of batter capacity.

[13] The step of permitting discharge of the

corresponding energy source in one embodiment comprises permitting zero current flow while the bus voltage exceeds the corresponding discharge voltage set point and permitting maximum current flow wh le the bus voltage is less than the discharge voltage set point. The method may employ a ramped transition between the zero current flow and the maximum current flow over a limited bus voltage range centered around the corresponding one voltag set point.

[14J In one embodiment, the comparing and permitting steps for each one of the energy sources may be carried out in a local processor dedicated to the one energy source, and carrying out the step of establishing discharge voltage set points in a central processor in communication with each local processor, and

communicating the corresponding voltage set point to the corresponding local processor,

[IS] The method in one embodiment further comprises:

establishing an EV recharge voltage set point for recharging the EV battery;

comparing the EV recharge voltage set. point with the voltage of the direct current bus;

permitting recharging of the EV battery from the direct current bus if the bus voltage exceeds the recharge voltage set point. In this embodiment, the method may further comprise:

establishing an EV discharge voltage set point for discharging the EV battery to the airect current bus

comparing the EV discharge voltage set point with the voltage of the direct current bus;

permitting discharge of the EV battery to the direct current bus if the bus voltage is less than the E discharge voltage set point,

[16] The method in another embodiment farther

comprises :

establishing an LESU recharge voltage set poin for recharging the local energy storage unit;

comparing the LESU recharge voltage set point with the voltage of the direct current bus;

permitting recharging of the local energy storage unit from the direct current bus if the bus voltage exceeds the LESU recharge voltage set point. [17] In a further embodiment, the method further comprises :

establishing a utility grid energy return voltage set point for selling energy through the utility grid;

comparing the utility grid energy return voltage set point with the voltage of the direct current bus ;

permitting current flow from the direct current bus to the utility grid if the bus voltage exceeds the utility grid energy return voltage set point.

[18] In a related embodiment, the direct current bus is coupled to the utility grid through a local AC

distribution panel, and the method further comprises:

establishing an AC panel backup voltage set point for flowing current from the direct current bus to an AC distribution panel;

disconnecting a local AC panel from the utility grid in the event of a utility grid failure;

comparing the AC panel backup voltage set point with the voltage of the direct current bus;

permitting current flow from the direct current bus to the AC utility panel if the bus voltage exceeds the AC panel backup voltage set point. The method of Claim 19 further comprising converting current flow from the direct current bus to the local AC panel from direct current to alternating current.

[193 The method may further comprises converting current flow from the direct current bus to the local AC panel from direct current to alternating current. [20] In a further embodiment, the method further comprises :

sensing a rate at which the EV battery is being charged, sensing a current charge level of the EV battery pack and competing a predicted charge completion time;

if the charge completion time is after the specified time, then performing a maximum rate charging operation toy discharging all of the energy sources to the direct current bus.

[21] In another aspect, a modular electrical power management system is provided for charging an electric vehicle (EV) frora plural energy sources, the EV having an SV battery and an EV charging port. The system

comprises :

a DC bus;

a control signal link;

a central processor coupled to the control signal link;

plural modules connected in parallel to the DC bus, each of the modules comprising a connection

terminal, the connection terminal of one of the modules being coupleable to the EV charging port, the connection terminals of the remaining ones of the modules being coupleable to corresponding ones of the energy sources, each of the modules further comprising:

a DC converter coupled through the connection terminal to the corresponding energy source and coupled to the direct current bus;

a local processor connected to the DC converter and coupled to the control signal link; and a memory coupled to the local processor.

[22J In one embodiment , the local processor is

programmed to cause the DC converter to enable current flow from the corresponding energy source whenever a voltage of the DC bus is less than a voltage set point stored in the memory, and the central processor is programmed to provide the voltage set point via the command signal link.

[233 n an embodiment, the DC bus comprises a pair of conductors, and each of the modules farther comprises a shunt capacitor connected to the pair of conductors.

[24] The plural energy sources may comprise one or more energy sources having zero energy costs and one or more energy sou ces having non-zero energy costs.

Alterna ively, the plural energy sources comprise at least one of a solar cell array and a wind generator, and at least one of a utility grid and a local energy storage u i t .

[25] In a further embodiment, an energy management system is provided for charging an electric vehicle (EV) having an EV charging port, the system comprising:

a direct current (DC) bus;

plural connector ports, one of the plural connector ports connectahle to the EV charging port, remaining ones of the plural connector ports connectaoie to respective ones of plural energy sources; respective DC converter stages coupled between respective ones of the plural connector ports ana the direct current bus;

respective local processors controlling respective ones of the converter stages and respective memories connected to the respective local processors; and

a central processor and a command signal link connecting the central processor to the local processors.

[26] In one embodiment, each local processor is

programmed to cause the corresponding DC converter to enable current flow from the corresponding energy source to the DC bus whenever a voltage of the DC bus is less than a voltage set point stored in the corresponding roeraory, and the central processor is programmed to provide the voltage set point to the corresponding memory via the command signal link.

[27] In another embodiment, the DC bus comprises a pair of conductors, the DC bus comprising a main DC bus and respective DC bus branches connected, to respective ones of the DC converters. Respective shunt capacitors are located at boundaries between the respective DC bus branches and the main DC bus, each of the shunt

capacitors connected to the pair of conductors.

[28] In one embodiment, the DC converter stages coupled to the remaining ones of the plural connector ports comprise respective discharge terminals, and respective diodes are connected between the respective discharge terminals and the DC bus in a polarity in which each diode is forward biased for current flow from the

respective DC converter stage to the DC bias. In this embodiment, the respective local processors are

programmed to control the respective DC stages to

maintain voltages of the respective discharge terminals at respective voltage set points, In an optional aspeot of this embodiment, the one DC converter stage associated with the SV charging port comprises a charging terminal, and a diode is connected between the charging terminal and the DC bus in a polarity in which the diode is forward biased for current flow to the one DC converter stage from the DC bus . The corresponding local processor is programmed to control the one DC converter stage to maintain voltage of the charging terminal at a selected voltage set point. The central processor is programmed to provide respective voltage set points to respective ones of the local processors.

BRIEF DESCRIPTION OF THE DRAWINGS

[29] So that the manner in which the exemplary

embodiments of the present invention can be understood in detail, a more particular description of the invention may be had by reference to the embodiments thereof which are illustrated in the appended drawings,

[30] FIG, 1 is a diagram depicting an arrangement for charging the battery pack of an electric vehicle, including an energy management system interfacing with multiple energy sources, in accordance with one

embodiment . C313 FIG . 2 is a diagram depicting the signal flow between the electric vehicle and the energy management system of FIG. 1.

[32] FIG. 3 is a diagram depicting elements within the energy management system of FIG. 2.

[33] FIG, 4 is a simplified block diagram depicting the simultaneous flow of power between a high voltage D.C. bus of the energy management system and the multiple energy sources, in accordance with one embodiment .

[34] FIG. 5A is a block diagram depicting power flow in a mode in which local renewable energy sources charge a local energy storage device in absence of the electric vehicle being connected to the system.

[35] FIG. 5B is a block diagram depicting power flow in a mode in which the electric vehicle s charged front available energy sources including the local energy storage device.

[36] FIG. 5C is a block diagram depicting power flow in a mode adapted to provide backup power during a utility grid power outage_*

[37] FIG. 5D is a block diagram depicting power flow in a mode in which both the local energy storage device and the electric vehicle'' s battery pack are charged

simul taneonsl . [38] FIG. 5E is a block diagram depicting power flow in a mode in which power is returned to the utility grid,

C393 FIG. 6 depicts the elements of a user interface of the energy management system of FIG, 1, and further depicts information flow from a multi-source utility grid supplier to the energy management system,

£ 03 FIG. 7 depicts one example of a menu screen of the user interface of FIG. 6.

[41] FIG, 8 is a flow diagram depicting one mode of operation of the energy management system of FIG. 2.

[42] FIG. 9 is a flow diagram depicting how to carry out the operation in FIG. 8 of charging of the on-fooard battery pack of the electric vehicle.

[43] FIG. 10 is a flow diagram depicting how to carry out the operation in FIG. 8 of charging of an energy storage device.

[44] FIGS. 11A and 11B are respective flow diagrams depicting how the energy management system decides to flow electric power back to a smart utility grid, in accordance with respective embodiment.

[45] FIGS. 12A and 12B depict a method of operation of the energ management system of FIG. 3 with interactive communication and control b the -user, in accordance with an embodiment . [46] FIG. 13 depicts how one or more of the rechargeable sources can be selected to be the recipient of power in the method of FIGS. 12A and 12B.

[47] FIG. 14 depicts a mode of the method of FIG 12 in which charging is performed in minimum time.

[48] FIGS. ISA, 158 and 15C depict embodiments of a mode of the metho of FIGS. 12Ά and I2B in which charging is performed at minimum cost.

[49] FIGS. 16A, 16B, 16C and 16D depict embodiments of a mode of the raethod of FIGS . 12A and 128 in which charging is performed using a maximum fraction of power derived from environmentally-friendly (green) energy sources .

[50] FIGS. 17A and 17B depict embodiments of a mode of the method, of FIGS. 12A and I2B in which charging is performed within a specified time_*

[513 FIG . 18 depicts an aspect of the method of FIGS. Ι2Ά and I2B in which charging is performed in accordance with plural modes selected by the user.

[52] FIG. 19 depicts a mode of the method of FIGS. 12A and 128 in which power is returned, to the utility grid.

[53] FIG, 20 depicts a mode of the method of FIGS. 12A and 12B for sensing a. power loss or outage of the utility grid and providing household backup power. [54] FIG. 21 depicts an energy management method in which an EV battery is held at an optimum long term storage voltage.

[55] FIG. 22 depicts an embodiment in which energy may be exchanged through the power management system with the utility grid, and in which backup energy may be provided to the household AC distribution panel in the event of a ailure or black out of the ability grid.

[56] FIG. 23 depicts modifications of the embodiment of FIG. 3, in which individual local processors control individual DC converters,, and in which filter capacitors are provided at the connections of the DC converters with the DC bus,

C573 FIG. 24 depicts a modular architecture for

carrying oat the embodiment of FIG. 23.

[58] FIG, 25 is a detailed view of a typical module in the modular architecture of FIG, 24,

[59] FIG. 26 depicts a method of operating the energy management system employing different bus voltage set points governing the discharging and charging of

different energy sources and energy sinks.

[60] FIG. 27 depicts a circuit useful in carrying out the method of FIG. 26, using diodes to govern current low from or to different energy sources and energy sinks in accordance with comparisons of respective bus voltage set points with the DC bus voltage. [61] FIG. 28 depicts a response of a DC converter in the embodiment of FIG. 26 in which a bus voltage set point is ramped,

[62] FIG. 29 depicts a method of operating an

individual iocai processor in accordance with a ramped bus voltage set point.

[63] FIG. 30 depicts connection of elements including a local processor in the energy management system for implementing the method of FIG. 29.

[643 FIG. 31 depicts a method or operation carried out in a local processor for controlling energy flow from the solar generator to the DC bus <

C 653 FIG. 32 depicts a method or opera ion carried cut in a local processor for controlling energy flow from the wind generator to the DC bos.

[663 FIG. 33 depicts a method or operation carried out in a local processor for charging the electric vehicle battery pack from the DC bus.

[67] FIG. 3 h depicts a method or operation carried out in a local processor for controlling discharging from the local energy storage unit to the DC bus.

[683 FIG. 34B depicts a method or operation carried out in a local processor for controlling discharging from the electric vehicle battery pack to the DC bus. [69] FIG. 35 depicts a method or operation carried out in a local processor for recharging the local energy storage device from the DC bus.

[70] FIG. 36 depicts a method or operation carried out in a local processor for controlling energy flow from the utility grid to the DC bus.

[71] FIG. 37 depicts a method or operation carried out in a local processor for returning energy to the utility grid from the DC bus.

[72] FIG. 38 depicts a method or operation carried out in the central processor for charging the electric vehicle battery pack at a maximum rate using a

combination of the operations of FIGS. 31, 32, 33, 34A and 36.

[73] FIGS. 39A, 39B, 39C, 39D and 39E together depict a method or operation performed by the central processor for charging the electric vehicle battery pack from the DC bus to a specified charge level at a minimum cost.

[74] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. Tt is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. it is to be noted, however, that the appended drawings illustrate only exemplary embodiments of this invention and are therefore not to be considered limiting of its scope,

DETAILED DESCRIPTION

[75] Referring now to FIG. I, an electric vehicle 100 has an electric motor 105 coupled to the vehicle wheels and powered by an on-board EV battery pack 110 contained in the electric vehicle 100, or an alternative

rechargeable energy storage device such as a capacitor bank, or fuel cell or the like. The battery pack 110 can be charged by an on-board charging system 115 that can be coupled through an external charging port 120 provided on the electric vehicle 100 to an A.C.

electrical outlet 125 while the electric vehicle 100 is parked. A charging cable 130 can be temporarily plugged into the charging port 120 at one end and can be plugged into the A.C. electrical outlet 125 at the opposite end. The on-board charging system 115 transforms the A.C.

power received from the outlet 125 to D.C. power at a. voltage appropriate for charging the on-board EV battery pack 110. The voltage of the D.C. power supplied by the on-board charging system 115 to the on-board battery pack 110 may be approximately 480 volts DC or in a range of 250-480 volts DC, for example. A battery management system 135 can monitor the condition of the on-board battery pack 110,, including battery texaperature and charge level, and signals the on-board. charging system 115 to stop charging whenever the battery pack 110 reaches a fully charged condition or whenever the battery temperature exceeds a predetermined limit, for example. The A.C. outlet 125 may foe a 110 volt outlet or a 220 volt outlet, for example. In these cases, the charging port 120 may be implemented wit a connector meeting the SAS J1772 specification for Level i (110 volt) and/or Level 2 (220 volt) sources .

[76] As discussed above, the on-board charging system 115 can charge the battery pack 110 at a rate that is limited by the capacity (maximum charging rate or

current-carrying capacity) of the on-board charging system 115. This capacity can be limited in order to reduce the size and weight of the on--board charging system 115. Moreover, the charging rate is limited by the power rating of the AC outlet 125, Such limitations have the undesirable effect of increasing the amount of time required to completely recharge the on-board battery pack 110,

C 73 In accordance with one embodiment, an energy management sys em 210 can be provided at the location (garage or car port) where the electric vehicle 100 is parked when not in use, and can provide electrical power to re-charge the on-board battery pack 110 through a detachable power cable 212. The energy management system 210 can be separate from the electric vehicle 100 and can manage power from numerous local sources, including power from the utility grid received through the household electric panel. The local sources can include renewable energy sources such as a wind-driven electric generator and/or a solar cell array or other off-grid electricity generator. The local energy sources may also include a local energy storage device such as an array of

rechargeable batteries. The energy management system 210 furnishes D.C. current at the required battery charging voltage directly to the battery pack 110, bypassing the on-board charging system 115, This permits the battery pack 110 to be charged at the maximum rate allowed by the battery management system 135, unlimited by the capacity of the on-fooa d charging system 115, The energy

management system 210 may be coupled to the battery pack 110 via a detachable charging cable 212 through a

charging port 155 adapted for a high voltage (e.g., 480 volts}, for example. The on-fooard charging system 115 would be used in circumstances where the energy

management system 210 is not available. Therefore, vehicle weight may be reduced by reducing the weight and power capacit of the on-board charging system 115 (or possibly eliminating it altogether) , This represents a less complex system, because o -boa d chargers have more stringent specifications than off-board devices (devices not on the vehicle) , such as off-board energy storage devices or AC/DC converters which can replicate the function of an on-fooard charger. The less complex system thus represents a lower total cost solution.

[78J FIG. 2 depicts an embodiment in which information and control signal paths are provided within the electric vehicle 100 and within the charging cable 212 to enhance operation of the energy management system 210. In the embodiment depicted in FIG. 2, the charging cable 212 can be removably connected, between the charging port 260 or 205 provided on the electric vehicle 100 and vehicle connector port 101 provided on the energy management system 210. The energy management system 210 is further coupled to receive power from any or all of the following sources: a utility grid 220 {e.g., via an electric power outlet), a local energy storage device 230 {which may be a battery array) , a wind turbine electric generator 240 ("wind generator") , and a solar cell array electric generator 250 ("solar generator") and/or an other off- grid electricity generator 253. For convenience, the energy management system 210 can have the following individual connector ports at which one end of a cable 212 may be removably connected: a utility grid connector port 221 connectable to the ability grid 220, a local energy storage device connector port 231 connectafoie to the local energy storage device 230, a wind generator connector port 241 connectable to the wind generator 240, and a solar generator connector port 251 connectable to the solar generator 250,

[79] In the embodiment of FIG , 2, the two different charging ports 260, 265 provided on the vehicle have different power capacities. For example, the charging port 260 ("port A") ma be a Level 3 port capable of receiving 480 volts DC, while the charging port 265 may be a combination Level 1 and Level 2 port adapted to receive either 110 volts or 220 volts. The charging cable 212 may include power conductor 214 and signal paths 216, 217, for example. The role of the signal paths 216, 21? will be discussed below.

[80] The electric vehicle 100 in the embodiment of FIG. 2 can have dual paths for the electric charging current, namely a high current path 271 directly coupled to the on-board batter pack 110 and bypassing the on-bo rd charging system 115, and a low current path 272 coupled to the on-board charging system 115. An output power path 273 is coupled from the on-board charging system 115 to the battery pack 110. Power from either charging port 260, 265 flows in a common power path 274 to a switch 275. The switch 275 can select one of the two power paths 271, 272 for power flowing from the charging port 260 (or from the charging port 265) . A switch controller 276 responds to a bypass signal transmitted from the energy management system 210. The bypass signal

indicates the presence of the energy management syste 210. The switch controller 276 responds to the bypass signal by configuring the switch 275 to couple power from the port 260 (or from the port 265) to the high current power path 271 that bypasses the on-board charging system 115. In absence of the bypass signal, the switch

controller 276 configures the switch 275 to select the low current power path 272.

[81] The switch controller 276 is coupled at the charging port 260 (or at the charging port 265} to the signal paths 216, 217 through signal paths 280, 281 extending between the charging port 260 and the switch controller 276. A charging control signal path 284 extends from the battery management system 135 to the switch controller 276 while another charging control signal path 285 extends from the battery management system 135 to the on-board charging system 115.

(Alternatively, the signal path 284 may extend directly f om the battery management system 135 to the charging port 260 or 265.) The charging control signal carried on each charging control signal path 284, 285 indicates whether charging is allowed (depending upon battery charge level and temperature sensed by the battery management system 135) . The energy management system 210 receives the charging control signal via the signal paths 284, 231 and 217. The bypass signal from the energy management system 210 follows the signal paths 216 and 280,

[82] FIG. 3 is a diagram of the energy management system 210 of FIG. 2. A high voltag DC bus 300 can be coupled through intelligently controlled electrical conversion modules to the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generator 250 and/or the other off-grid electricity generator 253. The voltage of the DC bus 300 can be predetermined, and may be lower than the voltage required for charging the o -boa d battery pack 110. A DC/DC converter electrical conversion module 305 can raise the voltage supplied by the high voltage DC bus 300 to the charging voltage required to charge the on-fooard battery pack 110 before it is delivered to the charging port (260 or 265} of the electric vehicle 100 of FIG . 2.

£833 Power flow through the charging port (260 or 265} may be bi-directional, so that in ome instances {to be described below) , power may flow from the on-board battery pack 110 to the high voltage DC bus 300. In such a case, the DC/DC converter electrical conversion module 305 reduces the DC voltage supplied from the on-fooard battery pack 110 down to the DC voltage of the high voltage DC bus 300. The direction of current flow may be controlled, by providing a small suitable voltage

difference, e.g., between the battery pack 110 and the high voltage D.C. bus 300. Current flow will be towards the lower potential . T is may be implemented by the DC/DC converter 305, for example, in accordance with known techniques . The DC/DC converter electrical

conversion module 305 may be intelligently controlled by a master controller 310 via a signal path 312a. In one embodiment, the master controller 310 can be a

programmable controller that can transmit a control signal via the signal path 312a to a control input of the DC/DC converter electrical conversion module 305. The control signal may be command to admit current or another command to halt current flow in the DC/DC

converter electrical conversion 'module 305.

[84] The utility grid 220 can be coupled to the high voltage DC bus 300 via an AC/DC electrical conversion module 320. The AC/DC electrical conversion module 320 provides conversion from AC to DC power for power flow in one direction, and conversion from DC power to AC power for power flow in the opposite direction. Power flow through the AC/DC electrical conversion module 320 may be bi-directional. For power flowing from the utility grid 220 to the high voltage DC bus 300, the AC/DC electrical conversion module 320 converts AC power to DC power and raises the voltage to the DC voltage of the high voltage DC bus 300. For power flowing from the high voltage DC bus 300 to the utilit grid 220, the AC/DC electrical conversion module 320 converts DC power at the voltage of the high voltage DC bus 300 to AC power at the voltage of the utility grid 220. Current flow direction will be toward the lower potential. This may foe implemented by the AC/DC electrical conversion module 320. The AC/DC electrical conversion module 320 may be intelligently controlled by the master controller 310 via a signal path 312b to a control input of the AC/DC electrical

conversion module 320. The AC/DC electrical conversion module 320 may block or conduct current flow in response to control signals frora the master controller 310. The signal path 312b may be bi-directional, in which case the AC/DC electrical conversion module 320 may transmit information back to the master controller 310 confirming its present status and/or conditions .

[853 The local energy storage device 230 (e.g. , an array of batteries or fuel cells or capacitors, etc. ) can be coupled to the high voltage D.C. bus 300 through a battery control electrical conversion module 325 and a DC/DC converter electrical conversion module 330. The battery control electrical conversion module 325 and the DC/DC converter electrical conversion module 330 may be bi-directional, and may be intelligently controlled by the master controller 310 via signal paths 312c and 312d extending to control inputs of the battery control electrical conversion module 325 and the D /DC converter electrical conversion module 330, respectively. The direction of current flow may be established by providing a small suitable voltage difference between the energy storage device 230 and the high voltage D.C. bus 300, in accordance with known techniques . Current flow will be in the direction of lower voltage. This may be

implemented by DC/DC converter electrical conversion module 330, for example. The batter control electrical conversion module 325 may monitor and control, via the signal path 312c, charging of the local energy storage device 230 based upon charge level and battery temperature, while informing the master controller 310 of its present status or condition of the local energy storage device 230. The battery control electrical conversion module 325 also monitors and controls

discharging of the local energy storage device 230, and/or informs the master controller 310 whether the battery charge level is sufficient to charge the on-board battery pack 110 of the electric vehicle 100.

[86] For power flowing from the looal energy storage device 230 to the high voltage DC bus 300, the DC/DC converter electrical conversion ^'module 330 boosts the DC voltage furnished by the local energy storage device 230 to the DC voltage level of the high voltage DC bus 300. For power flowing from the high voltage DC bus to the local energy storage device 230, the DC/DC converter electrical conversion module 330 reduces the high DC voltage supplied by the high voltage DC bus 300 down to a DC voltage near the battery voltage of the local energy storage device 230. This DC voltage may slightly exceed the battery voltage of the local energy storage device by an amount sufficient to efficiently charge the batteries of the local energy storage device 230.

[87] Renewable energy sources, such as the wind generator 240 and/or the solar generator 250 are coupled to the high voltage DC has through a renewable source DC/DC electrical conversion module 340. While FIG. 3 depicts an embodiment in which the renewable source DC/DC electrical conversion module 340 can foe shared between the wind generator 240 and the solar generator 250, plural renewable energy source DC/DC electrical conversion modules may be provided so t at each one of the renewable energy sources {e.g., the wind generator 240, the solar generator 250 and/or the other off-grid electricity generator 253) interfaces with the high voltage DC bus 300 through an individual DC/ DC electrical conversion module. Power flow through the renewable source DC/DC electrical conversion module 340 is in one direction only, i.e., toward the high voltage DC bus 300. The renewable source DC/DC electrical conversion module 340 may include a peak power tracking electrical

conversion module 342 and an isolated boost DC/DC

electrical conversion module 344, intelligently

controlled by the master controller 310, This control may be exercised over signal paths 312e and 312f

extending to control inputs of the power tracking

electrical conversion module 342 and of the isolated boost DC/DC electrical conversion module 344,

respectivel . The peak power tracking electrical conversion module 342 employs conventional techniques for selecting an optimum power level at which to operate respective ones of the renewable energy sources 240, 250. The peak power tracking electrical conversion module 342 further informs the master controller 310 of the power output of each renewable energy source 240, 250,

indicating whether adequate power is available from each one ,

[88] The master controller 310 can be programmed to intelligently manage each of the energy storage devices (the on-bo rd battery pack 110 and. the local energy storage device 230} and each of the energ sources (the utility grid 220 and the renewable energy sources including the wind generator 240 and the solar generator 250) so as to optimize efficiency while minimizing energy cost. For example, the master controller 310 causes the local energy storage device 230 to be charged from the renewable energy sources 240,, 250, if available, when the electric vehicle 100 is absent {or unconnected) .

Alternatively, the master controller 310 causes the local energy storage device 230 to be charged from the utility grid if the grid is at low demand rate at the current time, or if the renewable energy sources 240, 250 are currently unavailable or unproductive. The master controller 310 may undertake a complex decision based upon the current demand rate on the utility grid, the present power output levels of the renewable energy sources 240, 250, and the amount of time available to fully charge the renewable energy source.. The master controller 310 also decides which energy source to use to charge the on-board battery pack 110 when the electric vehicle 100 is present. Thus, the f stest charging of the cm-board battery pack 110 can be obtained from the local energy storage device 230 if the local energy source 230 is sufficiently charged.. This rate may- greatly exceed the rate at which the local energy storage device 230 is charged from the renewable energy sources such as the wind generator 240 or the solar generator 250, If for some reason the local energy storage device 230 is not sufficiently charged, then the master

controller 310 decides which of the other sources (the utility grid 220, the wind generator 240 or the solar- generator 250) would be best to use to charge the onboard battery pack 110, depending upon the present demand rate of the utility grid 220 and the respective output power levels of the wind generator 240 and the solar generator 250. The master controller 310 may employ more than one of those sources simultaneously to charge the on-board battery pack 110 w en the electric vehicle 100 is present, or to charge the local energy storage device 230 when the electric vehicle 100 is unconnected or absent .

£893 In one embodiment, the master controller 310 can configure the internal electric power or current flow paths within the energy management system 210 by issuing different control signals to selected ones of the

different electrical conversion modules, such as the DC/DC electrical conversion module 305, the AC/DC

electrical conversion module 320, the battery control electrical conversion module 325, the DC/DC converter electrical conversion module 330, the peak power tracking electrical conversion module 3 2 and/or the isolated boost electrical conversion module 344. The individual control signals enable or disable current flow through the respective electrical conversion modules and

establish a desired direction of current flow in those paths where current may flow in either direction

(bidirectional) . By individually enabling and disabling current flow through respective electrical conversion modules, the master controller 310 can cause current to flow exclusively between selected ones of the connector ports of the energy management system 210, including the vehicle connector port 101, the utility grid connector port 221, the local energy storage device connector port 231, the wind generator connector port 241 and the solar generator connector port 251. [90] In order to charge the on-board battery pack 110 from the local energy storage device 230, current or power flows via the high voltage DC bus 300 from the local energy storage connector port 231 to the vehicle charging connector port 101. In this case, the master controller 310 enables current flow through the battery control electrical conversion module 325 , the DC/DC

converter electrical conversion module 330 and the DC/DC converter electrical conversion module 305.

[91] In order to charge the local energy storage device 230 from the wind generator 240 or frora the solar

generator 250, current or power flows via the high voltage DC bus 300 from either of the renewable source connector ports 241 or 251 to the local energy storage connector port 231. In this case, the master controller 310 enables current flow through the battery control electrical conversion module 325, through the DC/DC converter electrical conversion module 330, through the peak power tracking electrical conversion module 342 and through isolated boost DC/DC electrical conversion module 344.

[92] In order to charge the local energy storage device 230 from the utility grid 220, current or power flows via th high voltage DC bus 300 from the utility grid

connector port 221 to the local energy storage connector port 231, In this case, the master controller 310 enables current flow through the battery control

electrical conversion module 325, the DC/DC converter electrical conversion module 330 and the AC/DC electrical conversion module 320,

C933 The master controller 310 may be further

programmed to supply excess or unneeded electric power to the utility grid 220. For example, if one or both of the renewable energy sources 240, 250 is producing a

sufficient level of electric power, or if the on-board battery pack 110 is fully charged, or if the local energy storage device 230 is fully charged, then the master controller 310 may decide to apportion power from any one or all of these sources to return power back to the utility grid 220, and earn a credit from the utility power supplier.

[94] FIG, 4 depicts the use of the high voltage D.C. bus 300 in the manner of an energy pool, in which power nay flow simultaneously in either one of two directions between the high voltage D.C. bus 300 and the electric vehicle battery pack 110, the local energy storage device 230 and the utility grid 220. Power flows in only one direction from the wind generator 240 to the high voltage D.C. b s 300 and from the solar generator 250 to the high voltage D.C. bus 300. Power flow between each of the energy sources 110, 220, 230, 240 and 250 and the high voltage D.C. bus 300 is shown schexaatic 11y as following respective power paths 112, 222, 232, 242 and 252. Many or ail of these power paths may conduct power

simultaneously, and in one embodiment may be constantly conducting power. The current flow and direction of current flow will depend, upon the relative abundance of power or need for power of the respective energy sources 110, 220, 230, 240, 250. In this manner of operation_,, the high voltage D.C. bus 300 acts as a pool of energy, to which excess energy can be supplied by some sources while other sources withdraw energy from the pool. The direction of current flow in the paths 112, 222 and 232 may change, as some sources become fully charged or depleted, or where power can foe returned to the utility grid 220 rather than being withdrawn from it.

[95] FIGS. 5A through 5Ξ depict different cases in which power flow is enabled only through selected ones of the power paths 112, 222, 232, 242 and 252 of FI . 4. In the case of FIG, SA, the electric vehicle 100 is absent, and the local energy storage device 230 can be charged from the renewable energy sources 240 and 250 while minimizing cost by refraining from charging the local energy storage device 230 from the utility grid 220. The case of FIG, 5A may be typical of a daytime use,

[96] FIG, 5B depicts a case in which the electric vehicle battery pack 110 can be charged b drawing power from the local energy storage device 230 and front the wind generator 240 (the solar generator 250 is shown not producing power, such as is typically the case at night) , In addition, and if required, the battery pack 110 may be charged by drawing power from the utility grid 220. The case of FIG. 5B may be typical of a nighttime use,

[97] FIG, 5C depicts a case in which the high voltage bus 300 is used to supply backup power to the household when the utility grid 220 experiences a. power outage or blackout. As indicated in FIG. 52, the utility grid 220 is coupled to t e high voltage bus 300 through an

electric utility panel 224 having a main switch 224-1 that interrupts connection to the utility grid 220, The main switch 224-1 In the embodiment of FIG. 5C does not interrupt the connection between the electric utility panel 224 and the high voltage D.C. bus 300. In the event of a power outage on the utility grid 220, the main switch 224-1 is opened {e.g., under control of the master controller 310 of FIG. 3) and backup power for the household flows to the utility panel 224 from the local energy storage device 230, and from either or both of the wind generator 240 and the solar generator 250, depending upon their output power levels. In addition, if

authorised by the user, backup power may also foe

withdrawn from the electric vehicle battery pack 110.

C983 FIG , 5D depicts a case in which the high voltage bus 300 is used to simultaneously charge both the battery pack 110 and the local energy storage device 230 from all available sources, including the utility grid 220, the wind generator 240 and the solar generator 250.

[99] FIG. 5E depicts simultaneous power flow from the local energy storage device 230, the wind generator 240 and the solar generator 250 to return power to the utility grid 220. Optionally, power may also be returned to the utility grid 220 from the battery pack. 110.

[100J Referring now to FIG. 6, the energy management system 210 may include or be connected, to a user

interface 350. The user interface 350 can be connected to the master controller 310, and in one embodiment ma be a computer, such as a personal computer 351 having a keyboard 352, a mouse 353 and a display 354 which may be a touch screen. Alternatively, or in addition, the user interface 350 may include a handheld or remote personal computing device 355 wi h i s own display 356. The remote personal computing device 355 may foe ceil phone or a smart phone, for example. The display 356 of the remote personal computing device 355 may be a touch screen, for example. The remote personal computing device may include a keypad 355-1.

[1013 The methods described below in this specification may be implemented by an application program 357 {in the form of firmware or software) stored in a memory of the master controller 310, and executed by the master

controller 310, In addition, the personal computer 351 may also contain an application program 358 that enables the personal computer 351 to function as the user

interface of the master controller 310, by providing prompts to the user, graphical displays of system

information and respond to commands or inputs from the user, in accordance with the methods described herein. Alternatively, or in addition, the remote personal computing device 355 may contain an application program 359 that enables the remote personal computing device 355 to function as a user interface of the master controller 310, by providing prompts to the user, graphical displays of system information and respond to commands or inputs from the user.

[1021 In the foregoing, the application program that implements the methods described herein is described as being the application program 35? that is stored in and executed by the master controller 310. In an alternative embodiment, such software may be included in the

application program 358 in the personal computer 351, with personal computer 351 performing some or ail of the tasks by controlling the master controller 310.

Similarly, in another alternative embodiment, such software may be included in the application program 359 resident in the remote personal computing device 355, with the remote personal computing device 355 performing some o all of the tasks by controlling the maste

controller 310.

[1033 FIG . 6 farther depicts the utility grid 220 as including an electric grid supplier 370 having main electric power generators 371 and an array of smaller electric energy sources that are high-cost peak demand electric power generators 372 (hereinafter referred to as peak demand generators) , which are kept, off-line until a. peak in utility customer energy demand occurs. In addition, various remote "green" sources of electrical- energy are available to the electric utility grid

supplier 370 via long power transmission lines, including a hydroelectric source 373, a geothermal source 374, a wind farm electric generator source 375 and a solar cell array electric source 376.

[104J The electric utility grid supplier 370 can change the price per kilowatt hour of electricit (utility rate) anytime during each day, depending upon the user demand . For exam le , at peak demand, the high cost peak demand generators 372 mast be brought on line, thus making it more expensive to provide energy, so that the utility rate is increased at that time. Depending upon

availability and other factors, the utility grid supplier 370 may be able to draw energy from any one of the green sources 373, 374,, 375 and 376, and change the fraction of the total energy provided by the green energy sources. In order to keep the customer informed of all such changes, a -utility information communication channel 380 is provided that carries the latest information

concerning the current utility rate and the current fraction of the energy contributed by green sources

("green fraction") . The master controller 310 or the personal computer 351 or the remote personal computing device 355 may be connected or coupled to the utility information channel 380. The utility information channel 380 may be implemented on the internet or it may be implemented as a local area network or as a signal carried on the power transmission lines or as a dedicated conductor or coaxial cable provided by the utility.

[1051 FIG. 7 illustrates one example of a menu window 390 displayed as a graphical user interface on the display 354 of the personal computer 351 or on the display 356 of the remote personal computing device 355 under control of one of the application programs 357 o 358 or 359.

[106J The menu window 390 includes a mode select drop^¬ down menu 392, in which the user can select the mode of operation from among a list of modes presented i the mode select drop-down menu 392. The illustrated, dropdown menu depicts modes that can be chosen, but does not contain an exhaustive list of all possible modes. The drop--down menu 392 includes buttons 393 that are labeled with the names of respective modes . A mode may be selected by clicking on the appropriate button 393 with a mouse or by touching the button 393 if the display 354 or 356 is a touch screen.

[1073 The menu window 390 further includes a recipient selection drop-down menu 23 , in which the user can select which one of the rechargeable energy sources

(i.e., the battery pack 110 or the local energy storage device 230) is to be the recipient of the energy

delivered via the high voltage bus 300. The illustrated drop-down menu: depicts key sources that can be chosen. The drop-down menus 394 includes buttons 395 that are labeled with the name of a respective rechargeable source. A source may be selected as the recipient by clicking on the appropriate hot button 395 with a mouse or by touching the button if the display is a. touch screen .

£1083 Any one of the application programs 357, 358 or

359 may include operational instructions or subroutines that optimise all energy sources in various modes.

Although execution of such instructions will be described as being carried out by the m ster controller 3.10, it is understood that they may be carried out by the personal computer 351, or the remote personal computing device 355, or a combination of them.

[1091 One example of operation of the master controller 310 is depicted in FIG. 8. The master controller 310 first determines whether either of the utility vehicle charging ports 260 or 265 is connected to the energy management system 210 (block 400 of FIG. 8) . This determination may be made by the master controller 310 sensing the presence of a flag signal transmitted by the electric vehicle 100 via the charging port 260 or 265. If the charging port is connected (YES branch of block 400}, then the master controller 310 commands the switch controller 276 to configure the switch 275 in the bypass position so that energy flows directly to the on-board battery pack 110 (block 405 of FIG. 8) . Thereafter, the master controller 310 manages ail the energy sources referred to above so as to optimize efficiency in

charging the on-board battery pack 110 (block 410 of FIG. 8} . The management operation of block 410 is illustrated in detail in FIG . 9, and is described below. This operation continues until a change in condition occurs, such as the on-board battery pack 110 reaching full charge, which is signaled to the master controller 310 by the battery management system 135,

£1103 If the charging port 260 of the electric vehicle 100 is not connected to the energy management system 210

(NO branch of block 400) , then the master controller 310 determines whether the electric vehicle 100 is completely unconnected (block 415 of FIG. 8) . if not (NO branch of block 415) , this means that the electric vehicle 100 is connected in the manner depicted in FIG. 1 to charge the on-board battery pack 110 through the on-board charging system 115. This charging may be continued to

completeness (block 420 of FIG. 8) .

3 tllij If either of the electric vehicle charging ports 260 and 265 is unconnected to the energy management system 210 {YES branch of block 415) , then any or all energy sources may be utilized to re-charge the local energy storage device 230. In this case,, the master controller 310 enables charging of the local energy storage device 230 (block 425) , The master controller 310 manages all energy sources to optimize efficiency in charging the local energy storage device 230 (block 430 of FIG. 8) .

[1123 The management operation of block 410 for charging the on~board battery pack 110 will now be described with reference to FIG. 9, The first step is for the master controller 310 to determine whether the local energy storage device 230 contains sufficient charge for

charging the on-board battery pack 110 (block 500 of FIG, 9) . This information may be obtained from the battery control electrical conversion module 325 of FIG. 3. If the local energy storage device 230 is sufficiently charged (YES branch of block 500) , then the master controller 310 enables current to flow rom the local energy storage device 230 to the high voltage D.C. bus 300 (block 510) . In order to avoid incurring utility costs, this selection may be rendered exclusive by blocking the power path from the utility grid 220 to the high voltage DC bcs 300.

[113J If the local energy storage device 230 is not sufficiently charged (NO branch of block 500) , then the roaster controller 310 determines whether the utility grid 220 is at an off-peak demand rate (block 515) . This determination may foe made by referring to a published schedule of utility rates, or by real time electronic inquiry via a smart utility grid. If the utility grid 220 is not currently at an off-peak demand rate (HO branch of block 515) , then the master controller 310 enables power flow from the wind generator 240 or the solar generator 250 (block 530) , unless neither is producing sufficient power. if the utility grid 220 is currently at an off-peak demand rate {YES branch of block 515), then the master controller 310 determines whether either the wind generator 240 or the solar generator 250 is producing sufficient electric power to render it preferable to the costly utility grid 220 (block 520) . This determination may be made by comparing the renewable source output power level to a predetermined power threshold, for example. If the power is sufficient (YES branch of block 520) , then the master controller 310 enables power flow frora the wind generator 240 or the solar generator 250 to the high voltage DC bus 300 (block 530) . Otherwise (NO branch of block 520} , the master controller 310 enables power flow from the utility grid 220 to the high voltage DC has 300 (block 525) . In this manner, the master controller 310 may explore numerous zero-cost or low-cost options before selecting utility grid power at a peak demand rate. During charging of the on-board battery pack 110, the master controller 310 continually monitors the charging conditions as indicated by the battery management system 135 (block 535) ·

[1143 The management operation of block 430 for charging the local energy storage device 230 will now be described with reference to FIG. 10. The first step is for the master controller 310 to determine whether the utility grid 220 is at an off-peak demand rate {block 615} . This determination may foe made by referring to a published schedule of utility rates, or by real time electronic inquiry via a smart utility grid. If the ability grid 220 is not currently at an off-peak demand rats (NO branch of block 615) , then the master controller 310 enables power flow from the wind generator 240 or the solar generator 250 (block 630) , unless neither is producing sufficient power. If the utility grid 220 is currently at an off-peak demand rate (YES branch of block 615) , then the master controller 310 determines whethe either the wind generator 240 or the solar generator 250 is producing sufficient electric power to render it preferable to the costly utility grid 220 (block 620} . If so (YSS branch of block 620) , then the master

controlier 310 enables power flow from the wind generator 240 or the solar generator 250 to th high voltage DC bus 300 (block 630) . Otherwise (HO branch of block 620) , the master controller 310 enables power flow from the utility grid 220 to the high voltage DC bus 300 (block 625) .

During charging of the local energy storage device 230, the master controlier 310 continually monitors the charging conditions as indicated by the local battery control electrical conversion module 325 (block 635) .

[115] As described above, power flow may foe bidirectional with respect to the utility grid 220, the local energy storage device 230 and the on-board battery pack 110. Thus, under favorable conditions detected by the master controller 310, if spare power s available, it isay be returned to the utility grid 220. The decision may be implemented in the master controller 310 as depicted in FIG. 1IA. If the local energy storage device 230 is not being charged (MO branch of block 640) and if on-board battery pack 110 is not being charged {BO branch of block 645), then the rrsaster controller 310 enables power flow from the high voltage DC bus 300 to the utility grid 220 {block 650) , The power may be furnished from any one or all of the following, depending upon availability: the local energy storage device 230, the on-board battery pack 110, the wind generator 240, and/or the solar generator 250, FIG. 11B depicts a modification of the embodiment of FIG. 11A, in which the order of operation of blocks €40 and 645 is reversed from that depicted in FIG . llh. In FIG. I IB, if the on-board battery pack 110 is not being charged (NO branch of block 645) and if the local energy storage device 230 is not being charged (MO branch of block 640, then the master controller 310 enables power flow from the high voltage DC bus 300 to the utility grid 220 {block 650) .

[1163 The methods of FIGS, 8-1 IB enable the energy management system 210 to optimize the use of the energy sources including the rechargeable energy sources (the on-board battery pack 110 and the local energy storage device 230), the renewable energy sources (the wind generator 240 and the solar generator 250) and the utility grid 220 to minimize cost. Thus, when the onboard battery pack 110 is not being charged,, the energy storage device 230 may be charged at a slow rate by a renewable energy source {the wind generator 240 or the solar generator 250) over man hours if necessary

(depending upon local wind speed or solar radiation) . After the local energy storage device 230 has been sufficiently charged, the on-board battery pack 110 of the electric vehicle may be charged at a very high rate by discharging the local energy storage device 230 to the on-board battery pack 110, to folly re-charge the onboard battery pack 110 in a relatively short time (e.g. , within less than one hour) . if the wind generator 240 and the solar generator 250 are not producing sufficient electrical power, the energy management system 210 may enable charging either (or both) the on-board battery pack 110 and/or the local energy storage device 230 from the utility grid 220, If the local energy storage device 230 or the on-board ba tery pack 110 or the wind

generator 240 or the solar generator 250 are providing sufficient power, the energy management system 210 may divert such power to the utility grid 220.

[117| The master controller 310 may be implemented as a programmed microprocessor that generates the required command signals described above to carry out the

operations described above automatically. in addition, user control ma be facilitated by including a user interface as a part of the master controller 310.

[1183 The energy management system 210 has been

described as having plural electrical conversion modules, including the DC/DC converter electrical conversion module 305, the AC/DC electrical conversion module 320, the battery control electrical conversion module 325, the DC/DC converter electrical conversion module 330, the peak power tracking electrical conversion module 342 and the isolated boost DC/DC electrical conversion module 344, While each of these electrical conversion modules has been described with reference to a particular

function, such as providing a conversion between

different DC voltages, or a conversion between AC and DC power, for exaxapie, such functionality may be provided in other devices rather than being provided within the particular electrical conversion module, or may be unnecessary in some embodiments. In the disclosed embodiment, there is at least one electrical conversion module between each energy source (the utility arid 220, the local energy storage device 230, the wind generator 240 and the solar generator 250) and the high voltage bus 300, each electrical conversion module being responsive to a control signal from the master controller 310 to block or conduct current flow through the particular electrical conversion module.

[1191 FIGS . 12A and 12B depict a method of operating the energy management system 210 in the complex environment of FIG. 6. In the method of FIGS. 12A and 12B, the application program is capable of operating the energy management system in any one of a number of different modes, These modes include a minimum time charging mode, a minimum cost charging mode, a green charging mode, a mode for charging within a specified time, operation based upon plural xaodes, a mode in which power is

returned to the grid, and a power outage monitoring and backup mode. The operational elements of each mode will be described below. The user interface 350 enables the user to select any one mode or to prioritize among

different xaodes . This may accomplished by displaying a menu window of the type depicted in FIG. 7, inviting the user to use the hot buttons in that window to select a mode, Almost all aspects of the method of FIGS. 12A and 12B, described below, involves a communication through the user interface 350.

[1203 The method of FIGS. 12A and 12B begins by

detecting the latest selection by the user of a mode (block 660 of FIGS. 12A and 12S) . The next step is to determine the power recipient, n mely the energy source to which power from the high voltage D.C. bus 300 of FIG. 3 is to be directed (block 662 of FIGS. 12A ana 12B) . An embodiment of the operation of block 662 is depicted in FIG . 13, discussed later herein,

[121] If the user-selected mode detected in the

operation of block 660 is the minimum charging time mode {YES branch of block 664), then the energy management system performs the minimum charging time mode (block 666), an embodiment of which is depicted in FIG. 14, discussed later herein. If the user-selected mode is the minimum cost charging mode (YES branch of block 668) , then the energy management system 210 performs the minimum cost charging mode (block 670) , an embodiment of which is depicted in FIG. ISA, discussed later herein. If the user-selected mode is the green charging mode {YES branch of block 672) , then the energy management system 210 operates in the green charging mode (block 674) in which the fraction of power from green sources is

maximized. An embodiment of the green charging mode is depicted in FIG. 16A, discussed later herein. If the user-selected mode is the mode of charging within a user- specified time (YES branch of block 676) , then the energy management systeiti operates in t e mode of charging within a specified time {block 678) , an embodiment of which is depicted in FIG. 17A. If the user-selected mode is a mixed mode operation (YES branch of block 680} , then the energy management system operates in the mixed mode operation (block 682} , an embodiment of which is depicted in FIG. 18. If the user-selected mode is the return power to grid mode (YES branch of block 684) , then the energy management system operates in the return power to grid mode (block 686) , an embodiment of which s depicted in FIG. 19, discussed below. If the user-selected mode is the utility outage back-up mode (YES branch of block 688} , then the energy management system 210 performs the utility outage back-up mode (block 690) , an embodiment of which is depicted in FIG. 20, In this mode, the software instructions governing this mode are executed in the background. This allows any other mode selected by the user to be performed and dominate the user interface 350. As soon as a utility power outage occurs, the utility outage backup mode takes over, terminating the previous mode, as will be described below with reference to FIG. 20.

[122J The determination of the power recipient of block 662 of FIGS. 12Λ and 12B is depicted in FIG. 13. A first step in FIG, 13 is to sense the user's selection of a power recipient (block 700 of FIG. 13}, which, may use the recipient selection window 394 in the display 390 of FIG. 7 to provide user interaction. Alternatively, the selection of the power recipient may be made

automatically by reference to user preference date previously entered into the system. If the power recipient selected by the user is the electric vehicle battery pack 110 {YES branch of block 702) , then power from the high voltage D.C. bus 300 is routed to the electric vehicle battery pack 110 In the manner depicted in FIG. SB, for example (block 704} , If the power recipient selected by the user is the local energy storage device 230 (YES branch of block 706) , then power from the high voltage D.C. bus 300 is routed to the local energy storage device in the manner depicted in FIG. 57A, for example (block 708} . If the user has selected both the battery pack 110 and the local energy storage device 230 to be a combined recipient (YES branch of block 710), then power frora the high voltage D.C. bus is routed to both the battery pack 110 and the local energy storage device 230 in the manner of FIG. 5D, for example (block 712) . The local energy storage device 230 may be

implemented as a rechargeable battery pack. In

accordance with various emhodixaents, the particular power distribution between the electric vehicle battery pack 110 and the battery pack constituting local energy storage device 230 can vary depending upon a variety of factors, including the level of charge of each pack, the tempe ature of each pack, the time of day, the scheduled use of each pack, the defined user distribution for each pack, and/or a combination thereof. If the user has made no selection (NO branch of block 710) or if the user designates the automatic selection mode, then the power recipient is selected in an automatic mode (block 714) . The first step of the automatic mode 714 is to determine whether the battery pack 110 is fully charged (block 716}. If so (YES branch of block 716), then a

determination is made of whether the local energy storage device is fully charged (block 718) . If this latter determination is confirmed {YES branch of block 718) , then, in accordance with one embodiment, the energy management system performs the return power to grid mode (block 720}, in which current from the high voltage D.C. is routed to the utility grid 220, in the manner of FIG. 5£, for example. In the determination of block 716, if the battery pack 110 is not fully charged (HO branch of block 716) _f then power from the high voltage bus 300 is routed to the battery pack 110 in the manner of FIG. 5E, for example (block 724) , In the determination of block 718, if the local energy storage device 230 is not fully charged (MO branch of block 718) , then power frorrs the high voltage bus 300 is routed to the local energy storage device 230, in the manner depicted in FIG, 5A, for example (block 722) ,

[1231 The mode of charging in minimum time of block 666 of FIGS. 12A and 12B is illustrated in FIG. 14. In FIG. 14, a first step is for the master controller 310 to survey each of the energy sources and determine the output power level of each in order to assess its

availability (block 730 of FIG. 14} . This determination depends upon both output power levels and the selection of the power recipient. Power is then routed from each available energy source via the high voltage D.C. bus 300 to the power recipient {block 732 of FIG. 14) . With the minimum-time charging mode the master controller will utilize the available energy sources to supply the maximum amount of power to the power recipient in order to minimize the time to charge the power recipient. In embodiments, the master controller may have a pre-defined (user or factory) preference as to the order of use of the available energy sources and the extent of that use (e.g. which to use f rst, and then next, etc, and the amount to use from each source) to reach the maximum amount of power. For example, the master controller may give priority to the solar generator over the utility as the solar power has no direct cost associated with it. Nevertheless,, in this mode the master controller would fill in the power needs with the utility or any other power sources having a cost of power, in order to meet the power requirements of minimum- ime charging of the power recipient.

[1243 The minimum cost charging mode of block 670 of FIGS, 12A and 12B is depicted in FIG, ISA in accordance with one embodiment. In the method of FIG, 15A, the master controller 310 surveys the power outputs of the energy sources to determine the availability of each (block 734 of FIG, ISA) . If the solar generator 250 is available, its output power is routed to the high voltage :·. :. bus 300 {block 735) . If the wind generator 240 is available, then its output power is routed to the high voltage B.C. bus 300 (block 736) . If the local energy storage device 230 is not the power recipient, and if it is available, then power from the local energy storage device 230 is routed tc the high voltage D.C. bus 300 (block 737) . The current energy rate or cost {e,g., dollars per kilowatt hour) of power from the utility grid 220 is obtained via the information channel 380 depicted in FIG. 6 (block 738). A determination is made of whether the utility grid, energy rate is below peak demand levels (block 739) . If so (YES branch of block 739), power flow from the utility grid 220 to the high voltage D.C. bus is enabled (block 740} . Otherwise (NO branch of block 739) , power from the utility grid is not used. The method of FIG, ISA at this juncture may cycle back to the step of block 734 or back to block. 660. In emfoodiraents, the rate or cost of power from the utility grid is obtained from any of a source including the internet, a wireless connection, predefined and stored value or values, and/or a user inputted value .

[125] In another embodiment of the minimum cost charging mode, each of the energy sources available to the

household (the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar

generator 250} has an associated energy rate or energy cost {in dollars per kilowatt hour) for the power that it provides, and the master controller 310 utilizes these costs to select what energy sources to use to provide power to the power recipient (via the high voltage D.C, bus 300) in such a manner as to keep the total energy cost below a desired limit or to minimize it. The particular energy cost for each energy source may be either set at given value (static) over time, or may be dynamic over time. The static energy cost is determined by a pre-defined value. For example, the household wind energy source (the wind generator 240) might have a fixed energy cost given the known average maintenance cost of the wind turbine over time. The local energy storage 230

(e.g., a rechargabie home battery) can have associated with it a cycle cost, which represents the wear and tear on the batter over time, e.g. the cost of the degrading of the battery over its life, and/or due to charging or operating the battery in a sub-optimal manner {e.g. when too hot, over charging, and the like) . In another example, the solar panels of the solar generator 250, not having a significant maintenance cost over time, may be assigned a zero energy cost. The dynamic energy cost can either be obtained from a pre-defined schedule providing energy cost for a given time {e.g., set in a look-up table storing cost as function of the time of day for use by the master controller 310) or can b received over time from reporting source. In one example of such reporting of the energy cost, the current rate {e.g., dollars per kilowatt hour) of the utility grid 220 is obtained via the information channel 380 depicted in FIG. 6. In such embodiments the system determines and stores the energy cost or value of the energy with which the local energy storage device has been charged (an average over time) , which can be used as the local energy storage device energy cost for use in the master controller's 310 selection of energy sources to supply power to the power recipient (e.g. either the battery pack 110 and/or the grid) to minimize costs,

[1263 This latter embodiment of the minimum cost charging mode is illustrated in FIGS. 15B and 15C.

Referring to FIGS, 15B and 15C, prior to performing the minimum cost charging mode, a system initialization

(block 741) is performed to define the energy cost of each power source (e.g. , the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generato 250} . For each power source having a substantially constant energy cost over time, the

constant energy cost is stored e.g., in memory accessible by the master controller 310 (block 742) . For each power source having a known time-varying (dynamic) energy cost, energy cost as a function of time is stored in memory, so that a particular energy cost may be fetched from memory for any value of time within a predetermined time range (block 743) . An optional operation is to assign an energy cost to the local energy storage device 230 based upon the cost of the energy that was used to charge the energy storage device (block 744} . This may be achieved by monitoring the utility rate charged by the operator of the utility grid 220 during the time (or times) that the local energy storage device 230 is charged frora the utility grid 220,, and

accumulating the energy costs thus monitored to provide an accurate accounting of the cost of the energy stored in the local energy storage device 230, (Such monitoring and accumulating is performed prior to the initialization operation of block 741.)

[127J Upon completion of the initialization of block 741, the system waits for the minimum cost charging mode to be selected (block 745) and does not enter the minimum cost charging mode if it has not been selected (MO branch of block 745) « Upon the minimum cost charging mode being selected (YES branch of block 745) , the minimum cost charging mode of block 746 is performed. The minimum cost charging mode of block 746 is in accordance with an embodiment different from the minimum cost charging mode of FIG, ISA. In block 746, for each power source having a known dynamic energy cost, the current time is noted and used to fetch the appropriate energy cost from memory (block 747) . For each power source having a dynamic energy cost whose schedule is no known to the system, the system {e.g., the master controller 310) obtains the current energy cost through a communication channel

{block 748) , The system may periodically update a schedule through a co municatio channel to keep the schedule up to date. For example, in the case of the utility grid 220, this information may be obtained through the communication channel 380. For each energy source having a static energy value, the static energy value is obtained from memory (block 749) . Static energy values can be entered into the system and updated through any of a variety of means including., but not limited to, user entry, software updates, data updates, and/ or via a communicatio channel . A desired energy cost limit may be obtained either from previously entered user

preference data or a new updated limit may be entered by the user via the user interface {block 750) or other means via the communication channel, such as a remote logon. In some embodiments desired cost limit may not be utilized, provided and/or available, as shown in the alternate path depicted in FIG 15B. In such cases the system will default to using the power source, or

combination of power sources, which provides the lowest cost .

[1281 The master controller 310 determines what

combination of power sources would, provide power at an energy cost not exceeding the limit or that is the lowest cost. It may do this, for example, by searching ail possible combinations of the power sources (block 751). For each combination, th effective energ cost is computed as a weighted average of the energy costs of the power sources of the particular combination, weighted in accordance with the power contribution of each source♦ The one combination providing the most acceptable results {e.g., the lowest cost or a cost below the desired energy cost limit) is chosen, and power flow from the power sources corresponding to the one combination to the high voltage DC bus 300 is enabled (block 752).

[129J The mode of.^" charging^' using a maximum fraction of power from green sources (green charging) performed in block 674 of FIGS. 12A and 12B, an e bodiment of which is illustrated in FIG. 16A. Referring to FIG. 16A, the power outputs of the household energy sources (i.e., the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generator 2505 are sensed to determine the availability of each source

(block 760) . For power from the utilit grid 220, the latest fraction of the total power contributed to the utility grid 220 from green sources (which may be

referred to as the green fraction or environmental value) is obtained through the utility information channel 380 (block 761) , In embodiments, the green fraction is obtained from any of a source including the internet, a wireless connection, predefined and stored value or values, and/or a user inputted value. The green fraction represents an environmental value of the energy in accordance with the proportion of non-polluting or renewable energy sources that contributed to the energy. However, the environmental value may instead represent an environmental cost or measure of carbon footprint or pollution. In the following examples, the environmental value corresponds to a green fraction, but embodiments are not limited thereto. A determination is made of whether the latest green fraction is above a

predetermined threshold value (block 762} . If so (YES branch of block 762) , power flow from the utility grid 220 to the high voltage D.C. bus 300 is enabled (block 763} . Otherwise (MO branch of block 762} , no power flows from the utility grid 220 to the high voltage D.C, bus 300. Power flow is enabled from the solar generator 250 if available (block 764) . Power flow from the wind generator 240 is enabled if available (block 765} . If the local energy storage device 230 is not the power recipient, and if power from the local energy storage device 230 is available, then power flow from the local energy storage device 230 to the high voltage bus 300 is enabled (block 766} . Thereafter, the energy management system 210 may return to the step of block 660 of FIGS, I2A and 12B.

[130J Determination of the utility grid power green fraction of block 762 of FIG, 16A may be carried out locally b the system using an environmental evaluation method based upon the environmental value of each one of the individual power sources available to the utility grid 220 (i.e., the on-site power sources 371 and 372, and the off-site renewable energy sources 373, 374, 375 and 376} . In various embodiments of the evaluation iaethod, each of the power sources 371-376 may be assigned a static or dynamic environmental value (stored in a lookup table} related to or determined from the nature of the power that they provide. For example, energy

provided by the solar cell array electrical source 376 of FIG. 6 may be given a preferred value compared to energy provided from t e hydroelectric source 374 or the wind farm electric generator source 375 {determined by a presumption that solar has less environmental impact than the other sources) . The foregoing is provided only as an exam le, and such determinations may be made i other ways. In this manner, the green fraction or

environmental value of the utility grid power may be accuratel determined, so that the predetermined

threshold of block 764 might be reached if a greater percentage of the utility grid energy is generated by sources with greater environmental values than otherwise. Of course such determination is dependent on the accuracy and detail of the information provided by the utility grid 220. A method in accordance with the foregoing for evaluating the environmental value or green fraction of the utility grid power is described below with reference to FIG. 16B.

[131J Referring again to FIG. 16Ά, performance of the operation of block 766 of FIG. 16A, in which power flow from the local energy storage device 230 is enabled, may be contingent upon the green fraction, or environmental value, of the energy stored in the local energy storage device. The energy stored in the local energy storage device 230 can be assigned an environmental value

corresponding to the environmental value of the energy with which it was charged (an average over time) , which can be used as its environmental value for selection by the master controller 310 of power sources to supply power to the vehicle batter pack 110. Thus, the master controller ma make a determination of whether to use power from the local energy storage device 230 based upon the envirosimental value of the power consumed in charging the local energy storage device 230. How this latter determination may be carried out is described below with reference to FIG. 16C,

[1323 Referring to FIG. 16B, a method of evaluating the green fraction of the utility grid power {used in the determination performed in block 761 of FIG. 16A) is now described. Evaluation is based upon an envi onmental value associated with each power source. The

environmental value may be equivalent to the green fraction (the fraction of power attributable to non- polluting or renewable energy sources) , so as to increase in magnitude with the environmentally desirable

characteristics. Alternatively, the environmental value may represent a cost, analogous to a carbon emission value, and may decrease in magnitude with environmentally desirable characteristics. in FIG. 16S, a system

initialization, depicted in block 767, is performed prior to the evaluation of the utility grid energy

environmental value. In the system initialization of block 767, a communication channel s ch as the

communication channel 380 of FIG. 6 may foe used to determine the various utility grid energy sources (e.g., the utility grid sources 371-376} that are currently on line to contribute power,, and their relative individual contributions to the total grid power (block 768) . For each utility grid energy source having a substantially constant environmental value, that value is stored in memory {block 769) . For each utility grid, energy source having a dynamically (time varying) environmental value, the environmental value is stored in memory as a function of time for a predetermined time range (block 770) . An optional operation is to assign an environmental value to the local energy storage device 230 based upon the environmental value of the energy that was used to charge the energy storage device (block 771). This requires prior monitoring of the environmental value of the power taken f om the utility grid 220 during the time {or times) that the local energy storage device 230 is charged from the utility grid 220, and accumulating the environmenta1 values thus monitored to provide an

accurate accounting of the environmental value of the energy stored in the local energy storage device 230.

[133J Upon completion of the initialisation of block 767, the system waits for selection of the maximum green fraction charging mode (block 772) . If no such selection is mad , the system waits (NO branch of block 772) . Once the maximum green fraction charging mode is selected (YES branch of block 772) , the system proceeds to determine the latest environmental value or green fraction of the utility grid power based upon the current time (block 773} . The evaluation operation of block 773 begins by obtaining the current level of power contributed by each utility grid energy source (block 774) . For each power source having a known dynamic envi onmental value, the current tirae is noted and used to fetch the present environmental value for the current time from memory (block 775)■ For each energy source having a static environmental value, the static environmental value is obtained from memory (block 776) . The environmental value of each energy source is assigned a weight

according to its power contribution relative to the other sources (block 777) , and the environmental value of the utility grid power is computed as a weighted average of the environmental values of the individual sources (block 778) . This is the value employed in the determination of the operation of block 761 of FIG. 16A. Other methods of computation may be performed to determine the utility grid power environmental value in accordance with the foregoing.

[134] FIG. 16C illustrates a modification of the maximum green fraction charging mode of FIG. 16Ά, in which a decision is made of whether to draw energy from the local energy storage device 230 depending upon the

environmental value or green fraction of the energy consumed in charging the local energy storage device 230. Referring to FIG. ; t , prior to the performance of the maximum green charging mode, charging of the local energy storage device 230 is xaonitored to determine the

environmental value or green fraction of the energy stored in the local energy storage device 230 (block 1750) . For example, during charging of the local energy storage device with utility grid power, the latest

environmental value (s) computed in the operation of block 773 of FIG. I6B are averaged over time. An overall average is computed by folding into this average a maximum green fraction or environmental value for any energy contributed, to the local energy storage device by the local renewable energy sources (the wind and solar generators 240, 250) . The resulting environmental value is stored for later use during performance of the maximum green fraction charging mode in deciding whether to use the local energy storage device 230 (block 1755) . [135] Continuing to refer to FIG, 16Cb when the maximum green fraction charging mode is selected, the power outputs of the household energy sources {i.e., the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generator 250} are sensed to determine the availability of each source (block 1760) . For power frorrs the utility grid 220, the latest fraction of the total power contributed to the utility grid 220 frorn green sources (which may be referred to as the green fraction) is obtained through the utility information channel 380 {block 1761) . A determi ation is made of whether the latest green fraction of the utility grid power is above

predetermined threshold value (block 1762) , If so (YES branch of block 1762), power flow from the utility grid 220 to the high voltage D.C, bus 300 is enabled (block 1763). Otherwise (HO branch of block 1762) , no power flows from the utility grid 220 to the high voltage D.C. bus 300. Power flow is enabled from the solar generator 250 if available (block 1764) . Power flo from trie wind generator 240 is enabled if available (block 1765) . A. determination is made of whether to draw power from the local energy storage device 230 (block 1766) , The determination of block 1766 is based upon whether the environment l value of the energy stored in the local energy storage device 230 is above a predetermined threshold. The environmental value of the local energy storage device 230 is obtained as the value previously stored in the step of block 1755. The determination of block 1766 ma involve additional criteria, e.g., determining whether the local energy storage device is available and that it is not the power recipient. If the local energy storage device environmental value exceeds the predetermined threshold (YES branch of block 1766} , and if the additional criteria are met, then power flow iron the local energy storage device 230 to the high voltage bos 300 is enabled {block 1767) . Otherwise (NO branch of block 1766) , power flow from the local energy storage device 230 is not enabled. Thereafter, the energy management system 210 may return to the step of block 660 of FIGS. 12k and 12B.

[1363 A variation of the embodiment of FIG. 16C is illustrated in FIG. 16D, Referring now to FIG. 16D, when the maximum green fraction charging raode is selected,, the power outputs of the household energy sources (i.e., the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generator 250) are sensed to determine the availability of each source

(block 2760) . For power from the utility grid 220, the latest fraction of the total power contributed to the utility grid 220 from green sources (which may be

referred to as the green fraction) is obtained through the utility information channel 380 (block 2761) . Then, a determination is made of the amount of utility grid power usable to provide an overall green fraction (from ail available sources) at or above a desired green fraction limit or threshold (block 2762) . Power flow is then enabled from the utility grid at the rate or amount determined in block 2762 (block 2763) . Power flow is enabled from the other available sources (block 2764). The process may then loop back (as indicated in dashed line) to block 2760 for a constant check of green power fraction, Otherwise, the process returns to block 660.

C137] The mode of charging within a specified time that is performed in block 678 of FIGS . 12Ά and 12B is

illustrated in FIG. 17A in accordance with one

embodiment. Referring to FIG. 17A, a specified time by which charging (e.g., of the electric vehicle battery pack 110} must be complete, is obtained (block 779} .

This may be done by referring to preferences that have been previously stored in memory, e.g., by the user.

Alternatively, this may be done at the last moment by prompting the user to enter the specified time via the user interface. The output power levels of a.1.1. the energy sources available to the household (i.e., the utility grid 220, the local energy storage device 230, the wind generator 240 and the solar generator 250) are sensed to determine the availability of each energy source and. to determine the total power currently

available to charge the power recipient (block 780) . The charge level or amount of electrical charge currently held in the power recipient is sensed (block 782) . From the information gathered in performing blocks 780 and 782, the charging time required to fully charge the power recipient is computed (block 784} , The time remaining until expiration of the specified time is computed, and a spare time is then computed as the difference between the time remaining and the required charging time (block 786) . If the spare time is not greater than a

predetermined threshold, e.g., zero or, preferably, a. safety buffer such as one hour (MO branch of block 788) , then the system cannot or should not charge in an alternative mode, and the energy management system returns to block 660 of FIGS , 12A and I2B. If the spare time is greater than the threshold {YES branch of block 788), then it is possible to charge in another

(alternative) xaode for a temporary period of time. The user's preference for the alternative mode {i.e., the user selected mode) is obtained either from preset preference data previously entered during initialization {or as a recent input from the user) , possibly in the form of a list with each mode ranked by preference (block 790) , For example, the charging could be carried out in the minimum cost charging mode temporarily. The

availability or viability of each mode ranked on the list obtained in block 790 is determined {block 794) . Of the ranked modes found to be viable in block 794, the mode with the highest ranking is then enabled {block 796) . Thereafter, the energy management system may then return to block €60 of FIGS . 12A and 11B. Alternatively, as indicated in dashed line in FIG. 17A, the system may return to block 786.

£1383 If the determination made in block 788 finds that ther is insufficient spare time, e.g., less than a safety buffer such as one hour {NO branch of block 788} , then the energy management system 210 performs the mode of charging in minimum time (block 798} , Thereafter, the energy manaqement system may return to block 660 of FIGS. 12A and 12B.

£1393 FIG . 17B depicts a modification of the method, as follows: In FIG. 178, the user preference (s) obtained in block 790 may be simply the designation of a single preferred, mode. The nex step is to determine the viability or availability of the preferred mode only (block 793) . Thereafter,, if the preferred mode is available (YES branch of block 793) , the preferred mode is enabled (block 795} . Otherwise (MO branch of block 793), charging is postponed. Such postponement or waiting is acceptable because there is spare time

remaining before the system would need to transition to the minimum time charging mode to achieve a full charge of the electric vehicle battery pack by the specified time. An example is that the user may be going away for the weekend., leaving the electric vehicle behind, and wants to have the vehicle battery pack fully charged by Monday morning. In such a case, during the weekend, the charging would be carried out cost-free at least part way via solar or wind charging by the wind generator 240 or the solar generator 250, and then Monda morning at an early hour (e.g. , 1:00am), charging from the utility grid 220 would foe initiated, to finish the charging on time.

[1401 A complete description of FIG. 17B is now given, A specified time by which charging {e.g., of the electric vehicle battery pack 110) must be complete, is obtained (block 779) . This ma be done by referring to

preferences that have been previously stored in memory, e.g. , by the user. Alternatively, this may be done at the last moment by prompting the user to enter the specified time via the user interface. The output power levels of all the energy sources available to the

household (i.e., the utility grid 220, the local energy storage device 230, the wind, generator 240 and the solar generator 245) are sensed to determine the availability of each energy source and to determine the total power currently available to charge the power recipient (block 780) . The charge level or amount of electrical charge currently held in the power recipient is sensed (block 782} . Frora the information gathered in performing blocks 780 and 782, the charging tirae required to fully charge the power recipient is computed (block 784) . The time remaining until expiration of the specified tirae is computed, and a spare tirae is then computed as the difference between the time remaining and the required charging time (block 786} . If the spare time is greater than a predetermined threshold,, e.g., zero or,

preferably, a safety buffer such as one hour (YES branch of block 788} , then it is possible to charge in another (alternative) mode for a temporary period of time. The user's preference for the alternative mode (i.e., a user selected mode) is obtained (block 790) . For example, the charging coxaId foe carried out in the minimum cost

charging mode temporarily. The availability of the preferred or user selected mode is determined (block 793) . If the user-selected mode is available (YES branch of block 793} , the user selected mode is enabled (block 795) , and determination is made of whether the charging is complete (block 797), If charging is complete (YES branch of block 797), the process returns to block 660, Otherwise (HO branch of block 797} the process returns to block 786. Considering again the determination of block 793, if the user selected mode is not available (MO branch of block 793) , then the process skips to block 797 for a determination of whether charging is complete . If charging is complete (YES branch of block 797) , the process returns to block 660. Otherwise (NO branch of block 797) the process returns to block 786.

C141] The mixed mode operation performed in block 682 of FIGS . 12A and I2B is illustrated in FIG, 18. Referring to FIG. 18, the user's rankings of the different modes in order of preference is obtained (block 800) . In one embodiment, the rankings have been previously entered as preset user preference data prior to operation. In another embodiment, the rankings may be entered

contemporaneously by the user via the user interface 350 in response to a system prompt,, for example. Once the user's rankings are obtained, the statas of each energy source ranked by the user is determined (block 804}.

The status includes information affecting the viability of the modes ranked by the user, and may include such characteristics as output power level, charge level (for a rechargeable energy source), green power fractio (for the utility grid) , utility rate or dollars per kilowatt hour (for the utility grid) , the environmental value or other relevant factors. From the foregoing status information, the viability of each mode ranked by the user is determined (block 806) . The mode of highest rank that is currently viable is determined, and that mode is performed (block 808} , The energy management system 210 may then return to block 804 or to block €60 of FIGS. 12A and I2B.

[142J The mode in which power is returned to the utility grid that is performed in block 686 of FIGS. 12& and 12B is illustrated in FIG. 19. The availability of each of the local renewable energy sources, including the wind generator 240 and the solar generator 250, is determined by sensing their respective output power levels (block 820) . Power flow to the high voltage D.C. fairs from each of the local renewable energy sources that is available is enabled (block 822) . The amount of charge in the local energy storage device 230 is determined (block 824) . If the charge is sufficient or above a

predetermined threshold (YES branch of block 826), then power flow to the high voltage D.C. bus 300 from the local energy storage device 230 is enabled (block 828} . Otherwise (HO branch of block 826) , the charge is insufficient, and the local energy storage device is not used. A determination is made of whether the electric vehicle battery pack 110 is fully charged or absent (block 8305. If not (HO branch of block 830}, a

determination is made whether there is spare time remaining before charging in the minimum time mode would have to begin to fully charge the battery pack by specified time defined in previously entered user preference data (block 832) . This determination of the spare time may be carried out in accordance with the operation of blocks 780, 782, 784 and 786 of FIG. 17A as described above, for example. Continuing with the description of FIG. 19, if it determined that the electric vehicle battery pack is fully charged or absent (YSS branch of block 830) or if it is determined that there is spare time (YES branch of block 832} - e.g., beyond a preset minimal value or bu er, then a

determination is made whether previously entered user preference data authorizes drawing power from the electric vehicle battery pack 110 (block 834) . If so (YES branch of block 834), then power flow from the battery pack 110 to the high voltage D.C. bus 300 is enabled (block 836) . Optionally, prior to enabling power flow from the high voltage D.C. bias 300 to the utility grid 220, a determination is made of whether the present utility grid energy rate is sufficiently high to warrant returning power to the utility grid 220 (block 837} . The determination of block 83? enables the system to maximize income on power returned to the utility grid 220, in a manner discussed below. The deter ination of the

sufficiency of the energy rate in block 337 may be made in accordance with a predetermined energy rate criteria. For example, the criteria may be that the energy rate lie within a range of energy rates charge by the operator of the utility grid during hours of peak power demand on the energy grid. Such information may be obtained via the communication channel 380 of FIG. 6 or may be predicted based upon prior energy rate trends observed on the utility grid. As another example, the criteri may be that, the energy rate be above a selected threshold. If the energy rate is sufficient (YES branch of block 837) , then the system enables power flow from the high voltage D.C. bus 300 to the utility grid 220 block 838), the utility grid 220 having been designated previously as the power recipient in the step of block 662 of FIGS. 12A and 12B. Otherwise {HO branch of block 837), powe flow to the utility grid 220 is not enabled, and the system either waits for the utility grid energy rate to increase to a sufficient level (block 839) , or returns to block 820 or to block 660 of FIGS. 12A and 12B.

[1431 Returning to the discussion of blocks 832 and 834, if it is determined that there is no spare time before minimum time charging roust begin (NO branch of block 832} or that drawing power from the battery pack is not authorized {NO branch of block 834), power flo to the utility grid is not enabled {so that the system can

concentrate on charging the electric vehicle battery pack} . The energy management system 210 may then return to block 820 (as indicated in dashed line) or to block 660 of FIGS, 12A and 12B.

[144] Returning the system to block 820 is advantageous, because, in those instances in which power is drawn from the electric vehicle battery pack 110, it prevents drawing down the electric vehicle battery pack charge below a level at which insufficient spare time remains in which to fully charge it in the maximum rate mode by a specified time, Whenever the system is drawing power from the electric vehicle battery pack 110, it recycles back to block 820 to ensure that the verification of block 832 is performed, once each cycle to ensure

sufficient spare time still remains. This cycle is rapidly repeated during the time power is drawn from the electric vehicle battery pack 110, to guard against depleting it to the point that the remaining spare time becomes insufficient.

£ 1451 It should be noted that inclusion of the optional determination of block 837 in the mode of FIG. 19 enables an embodiment for maximizing income from providing power to the utilit grid 220, by intelligently limiting the time windows during which the enabling of power flow to the utility grid. 220 in block 838 is performed. The time windows are defined using the determination of block 837 so as to maximize income from the utility grid operator. This maximizing income embodiment may exploit the

tendency of the utility grid 220 to credit power returned to the grid at an energy rate (dollars per kilowatt hour} equal to the rate at which users are charged for taking power from the utility grid 220. In this maximizing income embodiment, power would be delivered to the utility grid based upon either reaching a certain value of the current reported energy ra e and/or upon

predicted maximum value based on either pre-define values and/or an analysis of the history of reported maximum energy rates over time. To maximize such income, the local energy storage device 230, and/or optionally the vehicle battery pack 110, is/are charged by operating the system in the minimum cost charging mode as set forth above. Also, to maximize the income from providing power to the grid, the transfer of power to the grid is done as quickly as possible at a sufficiently high reported energy rate and/or at or about the predicted maximum energy rate.

£1463 The utility outage monitoring and backup mode performed in block 690 of FIGS . 12A and 12B is

illustrated in FIG. 20. The utility outage monitoring and backup mode can be implemented in a software or application prograxa that runs in the background while permitting a software or application of another mode to be performed and control the energy management system 210. Thus, in FIG. 20, the utility outage monitoring and backup mode runs passively while monitoring the utility grid 220 for a power outage, and while allowing one of the other modes of FIGS. 13-19 to be performed. After a power outage occurs, the utility monitoring and backup mode is active and replaces whatever mode the system was operating in at the time of the outage.

[147J Referring to FIG. 20, the current user-selected, mode, i.e., one of the modes of FIGS. 13-19, continues to operate (block 840) . In the meantime, the master

controller 310 monitors the power level of the utility grid 220 {block 842) . In block 844, determination that a utility grid power outage has occurred may he made, for example, whenever the sensed power or voltage level of the utility grid 220 falls below a predetermined

threshold. if a power outage occurs (YES branch of block 844) , then the system exits the current user-selected mode and causes the user interface 350 to notify the user (block 846). Then, as depicted in FIG. 5C, the master controller 310 causes the ain switch 224-1 to open and interrupt connection between the household electric panel 224 and the utility grid 220 (block 848) . This step leaves the household utility panel 224 connected to the high voltage D.C. bus 300. The master controller 310 verifies availability of each of the energy sources except the utility grid 220, namely the local energy storage device 230, the wind generator 240, the solar generator 250 and the battery pack 110 (block 850} , Power flow is enabled to the high voltage D.C. bus 300 from the wind generator 240, if available, and from the solar generator 250, if available (block 852) . Power flow from the local energ storage device 230 to the high voltage D.C. bus 300 is enabled (block 854), if power from the local energy storage device 230 is available. The local energy storage device 230 may not be available because the user may have made a selection to refrain from using it during a utility outage, as the user may want to keep it for later charging of the electric vehicle battery pack 110. in the case of a utility outage, in one embodiment the last power draw should be from the local energy storage device 230, because the local renewabl sources (the wind and solar generators) should be used first.

[148] A determination is made whether the previously entered user preference data, or recent entries by the user, contain an authorization to withdraw power from the electric vehicle battery pack in case of a power outage (block 856) , If such a withdrawal is authorized (YES branch of block 858) , then power flow from the battery pack 110 to the high voltage D.C. bus 300 is enabled (block 860) .

[149J In the backup mode described above, in the event, of a loss of power from the utility grid 220, the

household electric panel 224 is disconnected : ton. the utility grid 220 and power flows from the high voltage D.C. bus 300 to the household electric panel 22 .

Referring to FIG. 3, the D.C. power from the high voltage D.C. bus is converted to A.C. power at the household voltage for delivery to the household electric panel 224. The household electric panel 22.4 may distribute the power throughout the house. During this time, the master processor 310 periodically checks the power level on the utility grid 220 (block 862) . If power has been restored on the utilit grid 220 (YES branch of block 864), then the electric panel 224 is reconnected to the utility arid 220 by closing the master switch 224-1 {block 866), operation in the previously selected mode is resumed (block 868) and operation of the backup mode returns to block 840, Otherwise, if utility grid power has not been restored (NO branch of block 864) , the sys em continues to provide backup power to the household panel, while at the same time cycling back to the step of block 850 to re-verify the status of each source,

METHODS OF OPERATING

Optimizing hong Term £¥ Battery Storage ;

[1503 Many lithium batteries can utilize very high recharge rates (e.g. zero to fall recharge in less tha one hour) . For EV battery packs, this corresponds to power levels well beyond the capabilities of typical home circuits {even 220 volt circuits) « Battery life may be enhanced by more moderate recharge rates.

[1S1J Lithium batteries will generally last longer if stored at a charge level of about 50%, Calendar life is shorter when the batteries are stored at very high or very low states of charge. Significant over-charging, or over-discharging can destroy lithium cells. In view of these storage considerations, it can be desirable to fully charge the battery pack only rather shortly before intended use, thereby not allowing the cells to sit at full charge for extended periods of time. A remotely programmable embodiment of the system can offer a

convenient wa to top off charge level shortly before use; the user can signal that the EV needs to be fully charged by a certain day and. time, and the system can go into a rapid recharge .mode in anticipation of upcoming EV use (topping off the charge level may require only a few minutes) . Such an operation is depicted in FIG. 21, in which the EV battery pack 110 is initially maintained at a charge level of only a fraction (e.g._? 50% or between about 40% and 70%) of i s fell charging capacity {block 900 of FIG. 21), and kept at that charge level for long term storage, The master controller 310 remains ready to respond to communications from the user received via the user interface 350. The user interface 350 may include a. wireless link to an intelligent portable device held by the user, such as a smart phone. Whenever the user communicates a message defining a specific departure time (block 902), the main controller 310 begins a process of rapidly charging the EV battery pack 110 (block 904) .

For example,- the battery pack 110 may be maintained at a charge level of about 65% of capacity during normal storage, and the rapid charging of block 904 may take the charge level from 65% to about 95%. Such a charging operation may take only a few minutes using electrical power levels provided in a household electrical

distribution panel.

[1523 Recharging circuitry may be more efficient at some power levels rather than at others. For example, at high rates of recharge there is additional voltage drop in the conductor lines, whereas at very low charge rates the ''housekeeping power' required for the electronics may adversely affect charging efficiency. In one

embodiment, a determination of efficiency as a function of cha ge rate is made, and the master controller selects a charge rate that optimises efficiency. Summary of User Specified Modes of Operation;:

[153] The following are operational modes described below in which the EV batteries may be kept at a reduced charge evel that is ideal for long term storage, these modes being implemented in an EV energy management and conversion system similar to that of FIG. 3.

[1543 Minimum time EV recharge: The system evaluates the charge state of the EV that is connected to the system (which may be the ideal long term storage charge level or about 50%) , the charge state of the local energy storage unit, the capability of the utility panel (also local wind/solar sources) to deliver power, and the state of charge desired by the user {the user may not want or require a 100% full charge)■ The system delivers power to the EV at a maximum rate, commensurate with the EV's ability to accept power and the various combined source's abilities to deliver power, until the specified charge level is reached. The system can provide the user with a predicted time of charge completion and alert the user upon charge completion {including remote notification) .

[1553 Recharge to a specified charge level by a

specified future time: The system evaluates the

difference between the present EV state of charge and the state of charge requested by the user at a specified future time. The present EV state of charge may be the long term storage charge level, or about 50% of full charge in the case of lithium batteries. Based upon the charge difference and the available time period, the system delivers power to the EV at a rate that produces the specified state of charge by (or somewhat before) the specified, time. If the specified goal is not feasible (e.g. , the required rate would be above the maximum rate possible, the system can alert the user and provide information about the ma imum possible states of charge attainable at future times while proceeding to charge at the maximum rate. The requested future charge states may be called "charge state milestones" or "recharge goals". This mode can have an ongoing default schedule from day to day (e.g., a 95% charge every weekday morning at 7:15 am, in preparation for a morning commute) .

[1563 Minimum cost recharging mode: While operating within any other specified parameters (such as specified charge state milestones) , the system follows a recharging profile and strategy to minimize the cost of recharging the EV, and/or recharging the local energy storage unit.

[157| Green recharge mod : The system maximizes the proport ion of recharge power derived from renewable

(green) sources. The local wind and solar sources can be considered to be 100% "green'' . Power supplied by the utility grid may have a proportion of green power, provided by renewable sources. Information about the proportion of "green' energy on the grid might be

obtained via a communications link.

[158] Long-life storage mode: The system keeps the batteries at charge levels that contribute to maximum battery longevity (e.g., 40% to 65% or about 50% of battery capacity) . [1533 Minimum reserve charge: The system maintains the charge level of the EV and/or the stationary energy storage unit above a minimum prescribed level.

[160J Sell power to the utility grid mode : The system sends power back onto the utility grid, particularly at times of peak grid power demand and high power costs.

[1613 Backup power mode : The system disconnects local circuitry from the utility grid and provides backup power to a local area (e.g. through the local circuitry of the AC power distribution panel) . In order to provide isolation between the control of consumption of power from the utility grid and the control of backup power from local resources during a blackout on the utility grid, two separate grid power converters and ports are provided in accordance with one embodiment, one for normal grid connection and power seiiback and another for backup power flow in the event of a grid outage or other need for independent power. The grid power converters can incorporate the normal safeguards {e.g., of the type employed in grid-connected solar panel inver e s ) that prevent reverse flow of power when the grid is down. The backup power module can connect to the household power circuits through a mechanical switching device that assures that only one of the grid or the backup power module is connected to the household power circuits at any time. Such a feature is depicted in FIG. 22. A main switch 906 connects the AC distribution panel 224 to the AC utility grid 220, Two converter units a e

provided, a. bi-directional AC/DC converter 320-1 for controlling the power flow between the utility grid 220 and the DC bus 300, and DC/AC converter 320-2 for use during a utility grid blackout for controlling flow of power from the DC bus 300 to the AC distribution panel 224. The DC/AC converter 320-2 may include a

conventional element such as an inverter for producing AC power from the DC voltage of the bus 300. A switch 90S connects the distribution panel 224 to either the AC/DC converter 320-1 or to the DC/AC converter 320-2, An actuator 910 is linked to the switches 906, 90S so that whenever the switch 906 is closed, the switch 903 connects the distribution panel 224 to the AC/DC

converter 320-1, and whenever the switch 906 is open the switch 908 connects the distribution panel 224 to the DC/AC converter 320-2. The master controller 310 (or a local processor associated with the AC/DC converter 320- 1) controls the actuator 910 in response to conditions on the AC utility grid 220. As depicted in FIG . 22, the master controller 310 may control each of the power converters 320-1 and 320-2.

Mixed mode operation;

[162J A mixed raode operation operates in a manner: that combines attributes of more than one of the above modes, and can enable the system to automatically transition between different modes. An operating method described below is able to perform various functions of the above iaodes in harmonious combination and enable the user to customize the system performance into an operational mode that suits the user's wants and needs.

Cont o1 of the DC B; Voltage : [1633 Referring to FIG. 23, the voltage of the DC bus 300 may be regulated and allowed to fluctuate over a specified range in order to enable the various power converter units to function in a controlled and

harmonious manner . The DC bus 300 may beneficially foe provided with a capacitor or filter elements that help filter out voltage ripple and can moderate transient power surges. Capacitor filters such as shunt capacitors 912-1, 912-2, 912-3 and 912-4 are located between

different DC converters (e.g., DC converters 305, 320, 330, 340, 340'^' of FIG. 24) and the DC bus 300, and define boundaries between the DC bus 300 and separate bus branches 300-1, 300-2, 300-3 and 300-4. Each shunt capacitor 912-1, 912-2, 912-3 and 912-4 (shown in FIG. 24} filters voltage fluctuations in each individual

branch to reduce voltage fluctuations on the main DC bus 300. The DC bus 300 and its branches 300-1, 300-2, 300- 3, 300-4 each consists of two conductor's, e.g., a

positive conductor and. a negative conductor (not shown in FIG. 23), that provide a complete DC circuit. Each shunt capacitor 912-1, 912-2, 912-3 and 912-4 is connected across the two conductors of the DC bus 300.

Distributed Processing;

[1641 The power converters 305, 320, 330 and 340 may be independent, having their own can local processors 914-1, 914-2, 914-3 and 914-4, all responsive to the master controller 310. Hereinafter, the master controller 310 will be referred to as the central processor 310. Some of the processing tasks described herein may foe thus distributed throughout the system. The local processors 914-1, 914-2, 914-3 ,914-4 may run at higher processing rate or shorter cycle time while the central processor 310 runs at a much slower rate and supplies relatively slowly changing operating parameters to the fast-running independent local processors 914-1, 914-2, 914-3 ,91 -4. The independent; local processors 914-1, 914-2, 914-3 and 914-4 may execute fairly simple operating algorithms and may be able to utilize analog logic in their control loops. Control b the central processor 310 of the slowly changing parameters employed by the local

processors 914-1, 914-2, 914-3 and 914-4 provides great efficiency and flexibility. Remote or wireless control of the central processor 310 th ough the personal

computing device {e.g., smart phone) 355 of FIG. 6 provides versatility and convenience.

C165] The distributed processing architecture of Fig. 23 may be realized in accordance with the modular structure depicted in FIG. 24. There are plural separate modules 916-1 through 916-4 {or more, as desired, such as

additional modules 916-3' and 916-5) , each connected to the DC bus 300. Each module 916-1 through 916-4 is adapted to connect to a particular energy source or energy sink: thus, for example, the module 916-1

includes the DC/DC converter 330 which is adapted to be connected between the local energ storage unit {local SSU) 230 and the DC bus 300. Each module 916-1 through 916-4 may include an eiectricai plug assembly that allows it to be connected to {or form a part of) the DC bus 300, and a terminal 916a for connection to the particular energy sink or energy source associated with the module. Thus, terminal 916a of the module 916-1 is for connection to the local energy storage unit 230. The modules 916-1 through 916-4 further include the respective local processors 914-1 through 914-4 which control the

respective modules 916-1 through 916-4 in a semi- autonomous manner, the local processors 914-1 through 914-4 being provided with respective local memories 915-1 through 915-4. Thus, for example, the module 916-1 includes the local processor 914-1 controlling the DC/DC converter 330, and the local memory 915-1. The module 916-1 may be referred to as the local energy storage unit module .

[1661 he module 916-2 is the utility grid module, and includes the AC/DC converter 320 and the local processor 914-2 governing the AC/DC converter 320, and the local memory 915-2. The module 916-3 is the wind generator module that is connected to the wind generator 240, and includes the DC/DC converter 340 and the local processor

914-3 governing the DC/DC conv rter 340 and the local memory 915-3, The module 916-3' is the solar generator module that is connected to the solar generator {solar cell array) 250, and includes a D /DC converter 340 , a shunt capacitor 912-3' and a local processor 914-3'^' governing the DC/DC converter 340', and a local memory

915-3'. In th embodiment of FIG. 24, individual DC/DC converters 340, 340' and modules 916-3, 916-3' are provided separately for the wind power and. solar power generators 240, 250. In another embodiment, the modules

916-3 and 916-3' may be combined in a single module. The module 916-4 is the electric vehicle port module and includes the DC/DC converter 305, the local processor 914-4 governing the DC/DC converter 305, and the local memory 915-4. A coromunication path or signal line 917 provides communication between the central processor 310 and each of the local processors 914-1 through 914-4, Optionally, further modules may be included or added latery such as an additional module 916-5. For example, the module 916-5 may be for emergency backup power during a grid blackout, and may include a local processor 914-5 controlling the DC/AC converter 320-2 of FIG. 22. in suc a case, the module 916-5 is connected to the AC distribution panel 224. The arrangement of FIG. 22 may be employed, so that both the module 916-2 and the module 916-5 are connected to the switch 908 of FIG. 22.

[16?3 The user may purchase and install any combination of the modules 916, depending upon the household energy sources. For example, if the household energy sources do not include a wind generator, then the user may omit the wind generator module 916-3 from the system. If the user later acquires a wind generator, the the wind generator module 916-3 may be added to the system. The modules 916-1 through 916-4 may be connected in more than one manner. For example, each module 916 may include its own modular bus section 301 (shown in FIG. 25) , the

respective modular bus sections 301 of adjacent modules being removably connected to one another as the modules are mounted side-by-side in the arrangement of FIG. 24, so that the interconnection of the set of modules 916 forms the DC bus 300 from many modular bus sections 301.

[1683 FIG . 25 is an enlarged view of the module 916-1. The module 916-1 of FIG. 25 includes the DC/DC converter 330 and the shunt capacitor 912-1 located between the DC/DC converter 330 and the DC bus 300. The shunt capacitor 912-1 marks a boundary between the bus branch 300-1 and the DC bus 300. The module 916-1 further includes the local processor 914-1 and its memory 915-1. The local processor 914-1 controls the DC/DC converter 330 through a command link 919-1. A modular section of the signal link 917 may be included in the module 916-1. The signal link 91? may be a conductive path or it may be implemented as a wireless link, with individual wireless units being provided within the individual modules 916-1 through 916-4 as modular sections of the signal link 917. The memory 915-1 can store parameters transmitted over the signal link 917 by the central processor 310,

including bus voltage set points for charging and

discharging the EV battery pack 110, maximum current values, desired charging or discharging current levels, and software defining algorithms to be performed by the local processor 914-1. The module 916-1 is similar to the other modules 916-2 through 916-4 except that, in place of the DC/DC converter 330, one of the other converters is present (e.g., the AC/ DC converter 320 or the DC/DC converter 305 or the DC/DC converter 340) .

Snergy Management by Hierarch of Voltage Set Points :

[1693 The methods described below can employ a feature in which discharging an energ source to the DC bus 300 or recharging a rechargeable energy source from the DC bus is governed by selecting a hierarchy of different threshold voltages of the DC bus 300 for charging and discharging individual energy sources. These DC bus threshold voltages are referred to herein as bus voltage set points. The order in which different energy sources are permitted to discharge to the DC bus as the bus voltage fails is established by the relative magnitudes of their individual discharging bus voltage set points. Discharging of each energy scarce is enabled or disabled by comparing the present bus voltage with the bus voltage set point, for discharging that energy source.

Similarly, the order in which different energy sources are permitted to be recharged from the DC bus as the bus voltage increases is established by the relative

magnitudes of their individual recharging bus voltage set points. Recharging of each rechargeable energy source is enabled or disabled by comparing the present bus voltage with the bus voltage set point for recharging that energy source. The energy sources include the EV battery pack 110, the local energy storage unit 230, the solar

generator 250, the wind generator 240 and the utility grid 220, Of these, the EV battery pack 110 and the local energy storage unit 230 are rechargeable energy sources .

[1701 These priorities may be established in accordance with user preferences, for example, o in accordance with optimum priorities defined in information stored in the central processor 310, for example. These priorities may be reevaluated and adjusted periodically to accommodate changed circums ances. For example, a change in cost of grid power may render usage of energy from the local energy storage unit cost-effective or cost-ineffective. As another example in which priorities are to be

adjusted, the charge level of the local energy storage unit may become so reduced as to necessitate a reduction in use of its energy, or may become so great as to obviate any need for recharging it.

[1713 Referring now to FIG. 26, discharging of energy sources is governed in accordance with the following method: Priorities for discharging the different energy sources are established and/or periodically reevaluated in view of existing or changing circumstances, as referred bo above. Each time these priorities change, the energy sources are ranked in order of priority for discharging to the DC bus (block 940 of FIG 26) .

Individual discharging bus voltage set points are established for the individual energy sources, each discharging bus voltage set point being proportional to the discharge priority of the individual energy source (block 942) , For each individual energy source, its discharging bus voltage set point is compared with the voltage of the DC bus (block 944) . For each individual energy source, if the voltage of the DC bus is less than the discharging bus voltage set point, current flow is permitted by the corresponding power converter from the individual energy source to the DC bus, and otherwise current flow is prevented (block 946) .

[1723 Recharging the rechargeable energy sources from the DC bus is governed in accordance with the following steps: Priorities for recharging the different

rechargeable energy sources are established and/or periodically reevaluated in view of existing or changing circumstances, as referred, to above. Each time these priorities change, the rechargeable energ sources are ranked in order of priority for recharging from the DC bus (block 948 of FIG . 26) . Individual recharging bus voltage set points are established for the individual rechargeable energy sources, each bus voltage set point being inversely proportional to the recharging priority of the individual rechargeable energy source {block 950) . For each individual rechargeable energy source, its

charging bus voltage set point is compared with the voltage of the DC bus (block 952) . For each individual rechargeable energy source, if the voltage of the DC bus exceeds the charging bus voltage set point, current flow is permitted from the DC bus to the individual

rechargeable energy source, and otherwise current flow is prevented (block 954).

[1733 In the operations depicted in FIG. 26, the comparisons of the DC bus voltage with the different bus voltage set points may be carried out by the local processors 914-1 through 914-4 in accordance with

programmed, instructions reflecting the steps of FIG. 26. Alternatively, the comparisons may be carried out by hardwired logic. One example of such hardwired logic is depicted in FIG. 27, in which a first diode 918-1 is forward biased for current flow from a charging {output) terminal of the DC converter (e.g., the DC/DC converter 340) to the DC bus 300. Λ second diode 918-2 is forward biased for current flow in the opposite direction, i.e., from the DC brss 300 to a discharging (inpu terminal) of the DC converter (e.g., the DC/DC converter 340) . The local processor 916-1 receives the charging and

discharging bus voltage set points for the local energy storage unit 230 from the roaster controller 310 and causes the output terminal of the DC/DC converter 340 to be held at the charging bus voltage set point, and causes the input terminal of the DC/DC converter 340 to be held at the discharging bus voltage set point. Each

comparison referred to in FIG, 26 is fulfilled whenever the corresponding one of the diodes 918-1 and 918-2 becomes forward biased. While FIG. 27 depicts an

example employing the local energy storage unit 230 and its DC/DC converter 340, similar implementations may be used for each of the other energy sources.

[174] While the embodiments of FIGS. 26 and 27 may involve a discrete on/off switching threshold (defined by the bus voltage set points) producing a binary or

won/o££" response, the system may employ soft threshold voltages in which current flow is turned on in a ramped or smooth transition as the DC bus voltage increases (fo recharging) or decreases (for discharging) . This feature nay provide smoother voltage transitions on the DC bu 300. FIG. 28 is a graph depicting the concept of a ramped current response as a function of DC bus voltage relative to a bus voltage set point V_?, The current response may be ramped w thin a voltage band from V~ ~ Δ (below which the current is zero) to V_? e Δ (above which the current is at a pre-established maximum level) . The ramp function of FIG. 28 may be represented by a look-up table provided to the local processor 914-1 by the central processor 310. Operation of the local processor 914-1 to implement the soft threshold voltage is depicted in FIG, 29 using an embodiment of the module 916-1 partially depicted, in FIG. 30. The first step is to fetch the appropriate look-up table (block 920) . The bus voltage is measured (block 922) using a sensor 930 shown in FIG. 30. This voltage is employed by the local processor 914-1 to find the desired output current level from the look-up table {block 924) . Finally, while monitoring the actual output current using a sensor 935, the local processor 914 coxamands the DC/DC converter 340 to adjust the output current until the current measured at a sensor 935 reaches the value obtained from the lookup table {block 926) . While the foregoing is described as an example for the local energy storage unit 230, a similar method and structure may be employed to implement smooth or ramped bus voltage set points for each of the other energy sources, including the EV battery pack 110, the utility grid 220, th wind generator 240 and the solar generator 250,

[175] While the foregoing describes the implementation of ramped threshold voltages ^'using programmed processors, a ramped threshold voltage may b implemented using hardwired analog circuitry.

Variables Used in the Power Management Operations:

£1763 The operations and methods described below are defined with reference to certain variables which are as follows :

Tno ^« current date and time;

Tspecl - a first ^'user specified time (time #1); Tspec2 ~ a 2ⁱ'^:; specified time, etc.;

Especevl === a user specified EV energy level (EV charge level) at time #1;

Sspeclocall ~ a user specified local ESU energy level (local stationary energy storage unit charge level) at time #1; Tper2011-2-25-1525 === the time period between 3:25 and 3:26 pro on 25 February 2011 for time period lengths of one minute (another time period length may foe chosen if desired) ;

Tper - the length of each time period (e.g., one minute) ;

Cper2011-2-25-1525 = the cost of grid power in the time period between 3:25 and 3:26 pm on 25 February 2011 (this will often be a prediction or estimate) ;

Gper2011 -2-25-1525™ the renewable energy (green) fraction found within grid power in the time period between 3:25 and 3:26 pm on 25 February 2011;

Vevpack ~ the voltage of the electric vehicle energy storage unit or battery pack;

"bus = the voltage of the DC bus 300 , or a branch thereof;

Vbusmax - the maximum voltage prescribed for the DC bus 300;

Vbusmin - the minimu voltage prescribed for the DC bus 300 (when the system is *0N^r ) ;

Vev ~ the (DC) voltage of the EV charging port or conductor 214;

"solar ™ the voltage of the solar generator port 251;

Vwind - voltage of the wind power port 241;

Viesa - voltage of the local energy storage unit port 231;

"bussetlsolar === a first set bus voltage point variable used to regulate power flow into the bus from the solar generator port 251; Vfoussetlwind ^:::: a first set bus voltage point variable used to regulate power flow into the bus from the wind generator port 241;

Vbussetlev - a first set bus voltage point variable used to regulate power flow froirs the DC bus 300 into the BV port DC/DC converter 305;

Vbusset2ev = a 2^s bus voltage set point that may be used when the EV battery pack 110 is delivering power back to the DC bus 300;

Vbussetllesu ^::: a first set bus voltage point below which power flow is enabled, from the local energy storage unit 230 into the main DC bus through its

associated DC/ C converter 330, which may be referred to as a "discharge threshold voltage" {this variable will generally be a function of the state of charge of the local energy storage unit 230 or "LESO") ;

Vbusset2ies^'u - a 2^Λα set voltage point may be used when recharging the LESU, which may be referred to as a "recharge threshold voltage";

Aev ~ the current {amperes) flowing through the EV charging port or conductor 241;

Aspecev ~ a current level specified by the user or by the central processor 310 for charging the EV

Wev - the power (watts) flowing out of the EV charging port or conductor 214 to the EV battery pack 110, negative values indicating a flow of power in the reverse direction (i.e., from the EV battery pack. 110 to the DC/DC converter 305) ;

Asolar and Wsolar are current and power .levels at the solar port 251;

Wgrid ~ the power flowing out of the utility grid port 221, for selling power back to the grid (negative values indicate inflow of power, i.e. buying power f om the grid) ;

maxgridin ^~ the maximum power that is

permitted to flow from the grid 220 into the grid port 221 (generally limited by the current rating of the AC distribution panel 224);

Wmaxgridont = the maximum power that is

permitted to flow back to the grid 220 from the grid panel port 221 {this variable has a negative value when power is flowing back to the grid 220) ;

Amaxevout ===^; the maximum current (amps) that is permitted to flow out of the EV port or conductor 214 ( for EV charging) .

[1773 In the distributed processing architecture of FIGS. 23 and 24, the central processor {master

controller) 210 may control parameters, each as bus voltage set points, that are slowly changing, while the local processors 914-1 through 914-4 implement the high speed control methods that govern charging and

discharging operations of the respective energy sources. The fast running methods for implementation in the independent local processors 914-1 through 914-4 are the operations depicted in FIGS. 31- 37 below, and run fast in order to effectively regulate the current flow through their associated DC/DC or DC/AC converters. Optionally, the operations described below of the local processors 914-1 through 914-4 may foe implemented in analog (or digital) circuitry and incorporated into the operation of the ^Λchopping' or switching circuitry associated with the DC/DC converters. Switching frequencies generally exceed 10 kHz. Solar ceil array converter control method:

[178J A solar generator DC/DC converter control method is depicted in FIG. 31 and is described here with

reference to the systexa of FIG. 23 or 24. In the solar generator DC/DC converter control method, power only flows from the solar generator (solar ceil array) 250 to the DC bus 300. Since the solar energy is both free' and ''green' energy, power flow from the solar generator 250 can be fully enabled i all modes , as long as the system is ON" . The operation depicted in FIG, 31, generally designated as operation 1000, is performed by the local processor 914-3' (FIG, 24) and is as follows: A determination is made of the value of the set point voltage, Vbussetlsolar in accordance with the

predetermined priorities among the various energy sources as discussed above (block 1010 of FIG. 31) . The value of Vbussetlsolar can be set slightly less than the maximum allowed DC bus voltage, V usraa . A comparison is made of the present DC bus voltage (Vbus) and Vbussetlsolar (block 1020) . If Vbus < Vbussetlsolar (YES branch of block 1030) , then fall current flow is enabled from the solar generator port 251 to the DC bus 300 to deliver maximum power to the DC bus 300 as regulated by the peak power tracking stage 342 (block 1040) , Otherwise ( O branch of block 1030) , no such power flow is enabled. Rather than connect directly to the DC bus 300, the wind generator DC/DC converter 340 can feed power to a branch 300-3 of the DC bus 300 that connects to the main portion of the DC bus 300 via the filter 912-3, thereby allowing the branch voltage to fluctuate more than the main bus voltage . [1793 If there is little or no power going out from the DC bus 300 to the other ports, the voltage of the DC bus 300 will rapidly increase and the local processor 914-3' will quickly disconnect the solar generator 250 from the DC bus 300, s soon s any capacitors are charged and Vbus becomes greater than Vbussetlsolar . In this case bus voltage m y oscillate closely around Vbussetlsolar, provided the solar generator 250 is generating sufficient electrical power.

Wind generator converter control method:

[1801 The wind power method is similar to the method of FI G . 31, and is depicted in FI G , 32, The operation depicted in FIG. 32, generally designated as operation 1500, is performed by the local processor 914-3 and is as follows: The value of the bus voltage set point,

Vbussetl ind is determined in accordance with pre-defined priorities of the differen energy sources as discussed above (block 1510 of FIG . 32}, The value of Vbussetlwind can be set slightly less than Vbusmax. The present bus voltage (Vbus) is compared with Vbnsset1 wind (block

1520) , If Vbus < Vbussetlwind (YES branch of block

1530}, then full current flow is enabled from the wind generator port 241 to the DC bus 300 to deliver maximum power to the DC bus 300 as regulated by peak power tracking circuitry {block 1540).

[ 1811 I n one alternative embodiment, it is possible to combine the wind and solar power and feed them to the same converter, e.g., th converter 340 as depicted in FIG. 23. EV charge port control method:

[182J The control method performed by the local

processor 91 -4 governing the EV port DC/DC converter 305 is depicted in FIG. 33 generally as operation 2000. This operation proceeds as follows: A determination is made, using information provided by the central processor 310, of the specified EV charge current, Aspecev {block 2010 of FIG. 33) , This variable will have a value based upon the EV battery pack state of charge and, optionally, upon certain user specified parameters. A determination is made, using information provided by the central processor 310, of the bus vol age set point for the Ev port DC/DC converter 305, Vbussetlev {block 2020) . Generally, Vbussetlev may be fixed slightly above Vbnsmin. Compare Vbus with Vbussetlev {block 2030) . If Vbus > Vbussetlev {YES branch of block 2030) , then enable power flow from bus to the EV port at the specified rate, Aspecev {block 2040) . If not {HO branch of block 2030) , then disable power flow to the EV port (block 2045) . Thereafter, the system returns to the beginning, i.e., to block 2010.

[1833 I the power sources supplying the DC bus 300 are unable to provide the specified current Aspecev, the DC bus voltage will quickly drop below the bus voltage set point, Vbussetlev (Vbus < Vbussetlev) and the flow of current to the SV will be interrupted. The DC/DC

converter 305, under control of the local processor 914- , will continue to modulate the current flow by

switching between conduction and non-conduction; the voltage in the DC bus 300 will oscillate in a stable manner near Vbussetlev and power will be delivered to the EV at the maximum rate that the various power sources can provide. If the power sources feeding the DC bus 300 can handle the specified demand, then Vfous will stay above VbussetXev and current will continue to flow at the specified rate. As described above with reference to FIG, 23, in order to reduce voltage oscillations in the main DC bus 300 it may be desirable to interpose a filter stage 912-4 between the main DC bus 300 and the bus branches 300-4 connected di ectly to the branch or the DC bus, which is then connected to the EV port DC/DC

converter 305.

Local Energ Storage Unit Discharge Method.:

[3,843 A method of managing the discharging of the local energy storage unit (local ESU) to the DC bus 300, illustrated in FIG. 34A as operation 3000, is performed by the local processor 914-1, as follows: A

determination is made of the state of charge, Elesu, of the local energy storage unit or local ESU 230 (block 3010 of FIG, 34Λ) _r which may be information provided in rear time by the local ESU 230. Frora information

provided by the central processor 310, the local

processor 914-1 obtains the minimum reserve charge level , Eminlesu, that is required to be maintained in the local ESU 230 (block 3020) .

[1851 Next, a bus voltage set point {Vhussetllesu) for the local ESU DC/DC converter 330 is determined based on the relationship between Elesu and the minimum reserve charge Eminlesu. This determination may foe carried out by comparing Elesu with Eminlesu (block 3030} , If Elesu > Eminlesu (YES branch of block 3030) , then Vfouasetl iesu is set to a voltage between Vbnsmax and Vfousmin (block 3032). If not {MO branch of block 3030), then Vfoussetliesu is set to zero (block 3034) . A zero value for this bus voltage set point will prevent further discharge of the local ESU 230. The bus voltage set point, VbussetI lesu, for the local ESU 230 should

generally foe somewhat less than the bus voltage set points for wind and solar power, as this governs the priority of power acceptance and pats the wind and solar sources on line before taking power rom the local ESU. The relationship of the local ESU bus voltage set point to the bus voltage set point for grid supplied power may be varied according to conditions, such as local ESU state of charge and grid power cost, e.g. the local ESU bus voltage set point could be above the grid bus voltage set point when the local ESU has plenty of charge and/or when the cost of grid power is high, thereby favoring taking power frora the local ESU before using grid power.

[1863 Next, power flow is enabled from the .local ESU 230 to the DC bus 300 according to the relationship between the DC bas voltage Vbus and the bus voltage set point Vbassetlesu. This may foe carried out by comparing Vbus with Vbussetliesu (block 3040) , If Vbus < Vfoussetlesu (YES branch of block 3040) , then current flow is enabled t the maximum rate, Araaxdislesu, appropriate for

discharge of the local SSU 230 (block. 3050) . Otherwise (BO branch of block 3040), discharge of the local ESU 230 is not allowed. Operation then returns to the beginning at block 3010.

EV Battery Pack Discharge Method:

[1871 A method of managing the discharging of the EV battery pack 110 to the DC bus 300, illustrated in FIG. 34B as operation 3000' , is performed by the local

processor 914-4, as follows: A determination is made of the state of charge, Eev, of the EV battery pack 110 {block 3010' of F G, 34B) , From information provided by the central processor 310, the local processor 914-4 obtains the minimum reserve charge level, Eroinev, that is required to be maintained in the EV battery pack 110 (block 3020' ) .

[1881 Next, a bus voltage set point (Viusset2ev) for discharging the EV battery pack 110 is determined based upon the relationship between Eev and the minimum reserve charge Eiainev. This determination may be carried out by first comparing Eev with Eminev (block 3030'}· If Eev > Sminev (YES branch of block 3030'), then Vfousset2ev is set to a voltage between Vbus ax and Vbus in (block

3032') . If not (NO branch of block 3030'), then

Vbesset2ev is set to zero (block 3034' ) . A zero value for this bus voltage set point will prevent further discharge of the EV battery pack 110 to the DC bus 300,

[1891 If Vbus < Vbussetlesu (YES branch of block 3040'), then current flow is enabled at the maximum rate,

Ainaxdisev, appropriate for discharge of the EV battery pack 110 (block 3050') . Otherwise (MO branch of block 3040'), no discharge of the EV battery pack is permitted, Operation then returns to the beginning at block 3010' ,

Local SSU Recharging Method:

[190J as shown in FIG. 35, the local ESU 230 may be recharged from the DC bus 300 whenever the voltage of the DC bus 300, Vbus, exceeds the second (recharging) bus voltage set point for the local ESU 230, Vfousset2lesu .

93 For this purpose, t e local processor 914-1 periodically compares the DC bus voltage Vbus with the local ESU bus voltage set point Vbusset21esu {block 3052 of FIG . 35) , If Vbus exceeds Vbnsset21esu (YES branch of block 3052), then recharging of the local energy storage unit 230 from the DC bus is permitted (block 3054) . Otherwise (NO branch of block 3054), recharging of the local ESU 230 is not permitted, and the local processor 914-1 returns to periodically performing the comparison of block 3052.

Grid Po¾er Consum tion Operation :

[1913 A method for managing the consumption of power from the AC utility grid 220 to the DC bus 300, generally depicted in FIG, 36 as operation 4000, is performed by the local processor 914-2, as follows: The AC line voltage furnished by the utility grid 220 to the utility panel 224 is measured (block 4010 of FIG. 36} . Also, from information famished by the central processor 310, a circuit rrsaxirrsu ampere rating Arnaxacgrid. is obtained. Next, from information famished by the central processor 310, a bus voltage set point,, Vbussetlgrid is obtained {block 4020 ) . The set point Vhassetlgrid. can foe

approximately half way between the maximum and minimum bus voltages, or: Vbussetlgrid ~ (Vbusraax 4 Vbusmin} / 2, A comparison is made of Vbus and Vbussetlgrid (block 4030} . If Vbus < Vbussetlgrid (YES branch of block

4030), power is permitted to flow through the AC grid port 221 to the DC bus 300 at a current level not

exceeding Arnaxacgrid (block 4040) , The DC current associated, with the power delivered to the DC bus 300 may generally be different from the AC max current rating. If Vbus > Vbussetlgrid (HO branch of block 4030} , no power is allowed to flow from the utility grid port 221 to the DC bus 300 (block 4035) ,

Grid Power Sell-Sack Operation;

[1923 A method depicted in FIG. 37, as operation 5000, may be employed when power is flowing back to the AC utility grid 220 from the DC bus 300, for selling power back to the electric utility provider. A different grid bus voltage set point Vb«sset2grid may be employed in this ethod that is somewhat higher than the grid bus voltage set point Vbussetlgrid employed in the method of FIG. 36. The method of PIG. 37 is performed by the local processor 914-2 as follows: The AC line voltage

furnished by the utility grid 220 to the utility panel 224 is measured (block 5010 of FIG, 375. Also, from information furnished by the central processor 310, a circuit maximum ampere rating Amaxacgrid is obtained. Next, from information furnished by the central processor 310, a bus voltage set point, Vbusset grid. is obtained (block 5020) . The bus voltage set point Vbusset2grid can be approximately half way between the maximum and minimum bus voltages, or: Vbussetlgrid. ~ (Vbusmax. +

Vbusrain) / 2, and may be slightly greater than

Vb-asset1grid. A comparison is made of Vbus and

Vbussetlgrid (block 5030} . If Vbus > Vbussetlgrid (YES branch of block 5030) , power is permitted to flow to the AC grid port 221 from the DC bus 300 at a current level not exceeding Amaxacgrid (block 5040) . If Vbus <

Vbussetlgrid {NO branch of block 5030) no power is allowed to flow to the utility grid port 221 from the DC bus 300 (block 5035) . [1933 The operations of FIGS . 31-37 are intended for operation by the local processors 914-1 through 314-4 at a relatively high speed (e.g., 20 kHz) .

Maximum Rate Recharging of the EV Battery Paok to a

Specified Charge Level;

[1943 A method of charging the EV battery pack 110 to a specified charge level at a maximum rate, depicted in FIG. 38 as operation 7000, is perf rmed by the central processor 310, and involves cooperation of the local processors 914-1 through 914-4. The method proceeds in the following raar er : Maximum EV charge current

Amaxevout and maximum EV charging power Wmaxevout are obtained by communication with the EV battery management system 135 of FIG. 3 (block 7010 of FIG , 38} . The EV battery management system 135 may foe able to provide the present maximum rates directly. Alternatively, a lockup table can be used to find the maximum rates based on the current state of charge, temperature, ana other

variables. The present EV state of charge, Enowev, is obtained from the EV batter management system 135 {block 7020) . For optimum long term storage, the EV present state of charge may be at 50% of battery capacity, for example. A user-defined desired EV charge level or goal, Sspecevl, is obtained, for example through the user interface 350 (block 7030) . This may foe any level up to 100% of battery capacity. The values of Enowev and

Sspecevl are compared (block 7040) . If Enowev < Especevl (YES branch of block 7040), then the specified EV charge current (Aspecev) is set to the maximum allowable current Amaxevout, so that Aspecev === Amaxevout (block 7050) , and the central processor 310 causes the different local processors 914-1 through 914-4 to perform the respective operations 1000, 1500, 2000, 3000, 3000' and 4000 {block 7055). Otherwise (NO branch of block 7040), no charging is permitted and the user is aierted (block 7045) .

SV Recharging Operation to Specified Charge Level At

Minimum Cost:

[1953 The following operation combines many attributes of the features previously described with reference to FIGS . 21-38. These features include adjustment of the bus voltage set points of different energy sources depending upon changed priorities, the maximization of the use of free or renewable energy sources and

minimization of usage of costly non-green energy sources, with intelligent prioritization of the different energy sources and assessment of energy cost profiles and green energy availability projections (e.g. , based upon weather predictions and sunlight predictions) . The following operation responds to a user command to charge the EV to a user-selected charge level by or before a user-selected time, while apportioning the consumption of free

(renewable) energy and utility grid energy without depleting rechargeable energy sources, and scheduling consumption of utility grid energy so as to minimize energy cost while simultaneously maximising the

consumption of green energy.

[1963 The free energy sources are green energy sources, and include the wind generator 240 and the solar

generator 250, bat these are limited by weather and sunlight conditions. The utility grid 220 is unlimited in its availability, but can be expensive depending upon the time of day of energy consumption. The local energy storage unit 230 stores energy that may be derived from the free energy sources 240 and 250 and from the utility grid 220 during times of low energy costs (e.g., at night) . Thus, the free energy sources are preferred above all, the local energy storage unit 230 may be preferred if the cost of the energy its currently stores is less than the prevailing grid energy costs, while the utility grid 220 is used to a minimum extent required to meet the requirements of the user's charging command whenever it cannot be met by a combination of all the other energy sources. But, grid usage in this operation is made in accordance with an optimum selection of time periods in which grid costs are minimal. These

elements are fulfilled by the highly versatile recharging operation illustrated in FIGS. 39A. through 39D, and performed by the central processor 310.

[ 197 | The recharging operation consists of several phases, each phase fulfilling a particular purpose. In a first phase, the central processor 310 surveys the basic conditions and costs of the different energy sources and of the EV, and references them to the user's command specifying the desired EV charge level and the completion time. This first phase consists of blocks 8010 through 8070 of FIGS . 39A and 39B, In the next (i.e., second) phase, it is first determined whether the local energy storage unit stores energy that is costly relative to grid energy cost and whether it has suf icient energy, by itself, to fulfill the -user's command. In this second phase, if the local ESU energy is insufficient or

relatively costly, then it is to be supplemented with utility grid energy, in which case the utility grid energy and local ESO energy are placed at equal priority by setting their bus voltage set points to the same level. Otherwise, if the local ESU energy is sufficient, its bus voltage set point is set at a higher level to increase priority of its usage relative to utility grid energy. This second phase includes blocks 8075 through 8140 of FIGS . 39B and 39C. In a third phase, the decision has been made to employ a combination of both local SSU energy and utility grid energy because the local ESIT energy by itself is insufficient. In order to minimize cost, the utility grid energy usage is minimized so as to provide just enough utility grid energy into the energy pool to fulfill the energy requirement of the user's command. This is accomplished by an intelligent search for a threshold cost level above which the utility grid energy is not used during successive time periods, and below which a sufficient number of time periods qualify for utility grid energy to fulfill the energy requirement by or before the user-specified completion time. This third phase includes blocks 8150 through 8210 of FIG. 39D.

£1983 After receiving a user command that the SV battery pack is to be charged to a specified, energy (charge) level, Especlev, by a specified time, Ispecl, the

recharging operation of FIGS. 39A through 39D proceeds as follows: An estimate is obtained of the local renewable

(green and. free) energy (Egrnest) available between the present me, Tnow, and the user designated time for SV charging completion, Ispecl (block 8010) . This estimate may be based on local weather predictions, for example. Based upon the specified, charge level Especlev to which the EV is to be charged, a determination is made of the recharge energy, Ereqev, required to reach the specified charge level, in accordance with the following definition: Ereqev ·■·■- Especlev - Eno ev (block 8020) . If Ereqe < 0 {YES branch of block 8025), no further

charging is required,, the charging is stopped and the user alerted (block 8027), Otherwise (MO branch of block 8025) , the operation proceeds to a calculation in block 8030 of the additional required energy Eaddev beyond the local green energy Egrnest, This calculation is made as follows: Eaddev = Ereqev - Egrnest. If Eaddev is not greater than zero (MO branch of block 8040) _? then no energy rom non-green sources is required, and the operation proceeds to perform maximum rate green charging in block 8120 from the wind generator 240 and solar generator 250 by enabling the operations 1000, 1500 and 2000 previously described herein.

[1991 Otherwise (YES branch of block 8040), additional energy from non-green sources, such as either or both the local energy storage unit 230 and the utility grid 220 is needed, A determination is made of an optimum mixture of energy from the local energy storage unit 230 and the utility grid 220. This determination involves a

comparison of the cost of energy stored in the local energy storage unit 230 with the cost of energy from the utility grid. This comparison is carried out by first obtaining a profile of the predicted cost of energy from the utility grid 220 for the time period of interest, namely Tnow to Tspecl (block 8050) . From that profile, a determination is made of the minimum cost of utility grid energy in that time pe iod, Cmingrid (block 8055) . This information may be obtained from the grid utility

provider, for example. A determination is made of the cost of energy that was used to charge the local energy storage unit, Ccrglesu (block 8060) . This determination may be based upon information previously stored by the local processor 914-1 of utility grid costs that

prevailed during the charging of the local energy storage unit 230 and the proportion of utility grid energy stored in the local energy storage uni 230. A determination is made of the present charge level of the local energy storage unit 230 (Enowlesu) and its minimum reserve state of charge (Ereslesu) {block 8062) . Enowlesu may be obtained from the local energy storage unit 230 and

Ereslesu may be supplied by the central processor 310. Then, the available local energy storage unit {local ESU) energy {Bavilesu} is calculated in accordance with the following definition: Eavllesu - Enowlesu - Ereslesu (block 8064) .

[200| The cost, Cerglesu, of the energy stored in the local ESU is compared with the minimum grid energy cost in the time period Tnow to Tspecl , Cmingrid (block 8070) . If Cerglesu < Cmingrid {YES branch of block 8075, this indicates that the local ESU energy is less costly than the utility grid energy, in which case the operation proceeds to block 8080 for a determination of whether the local ESU energy, without utility grid energy, is

sufficient, as will be discussed below. Otherwise {IMG branch of block 8075) , the local ESU energy is s costly as the utility grid energy, so that th two may be mixed. Therefore, the operation proceeds to block 8150 which begins the group of operations (blocks 8150 through 8200) in which an adequate energy mixture is found, in which the utility grid, enerqy is drawn during time periods selected to minimize cost, as will be described later herein . [2013 Referring again to the operation of block 8080, the sufficiency of the energy stored in the local ES0 230 is determined by a comparison of the available local ESIJ energy, Eavllesu, and the additional energy required,

Eaddev. If Eavllesu > Eaddev (YES branch of block 8080), then the local ESU energy is sufficient and utility grid energy is not needed, Therefore, the central processor 310 puts the bus voltage set point for discharge of the local SSU (Vfoussetlles ) to a value that is somewhat higher than the grid power set point {vbussetgrid} , so that local ESU discharge takes a higher priority {block 8090} , Charging of the EV battery pack is then carried out in accordance with the operations 1000, 1500, 2000 and 3000 by the corresponding local processors 914-1 through 914-4 (block 8100) , The operations 1000 through 3000 may be carried out at operating speeds as much as 10,000 times faster than the operations by central processor 310.

[2021 If the comparison of block 8080 find that Eavllesu < Eaddev (MO branch of block 8080) , then the local ESU energy is insufficient, and it will need to be

supplemented with utility grid energy, and therefore the priorities for use of utility grid energy and local ESU energy sho ld foe made the same. Accordingly, the bus voltage set point for the local ESU discharge,

Vbussetliesu, is set to a value that is equal to the bus voltage set point for the utility grid, Vbussetgrid

(block 8140} . Charging of the EV battery pack is started or continued, by enabling the operations 1000, 1500, 2000 and 3000 to run on their respective local processors (block 8142) . In order to account for the availability of the local ESU energy, the value of the additional required energy, Eaddev, is rese in accordance with:

Saddev ^::: Eaddev ^■■■ Eavliesu {block 8144) . Operation then proceeds to block 8150, which begins the group of

operations {blocks 8150 through 8200) in which an

adequate energy mixt re, including continuous local ESO energy and utility grid energy drawn during tirae periods of minimised cost, is found.

[2033 In blocks 8150 through 8200, the central processor 310 determines the time periods during which utility grid energy may be used at mi imum cost to furnish the needed additional charge Eaddev. This is done by finding a cost threshold below which grid, energy may foe drawn during an individual time periods of adequate number to meet the charge requirement. Referring now to the operation of block 8150, a calculation is made of the length of time required { perreqgrid) for the grid power connection to provide the additional energy required (Eaddev) at maximum rate grid supply rate ( maxgridin) . This

calculation is carried out in accordance with the

following definition: Tperreqgrid - [Eaddev /

Wmaxgridin] k, where k is a constant providing an

appropriate conversion of units. The constant k can be readily ascertained by the skilled worker, A cost threshold variable (Cthresh) is initialized to a value that is equal to the minimum grid energy cost (Cmingrid) , so that: Cthresh === Cmingrid (block 8160) , The value of the threshold cost Cthresh is increased by a small increment (Cine), so that: Cthresh - Cthresh + Cine

(block 8170) . The increment Cine may be about 2% of a typical minimum power cost, for example. The

individual costs of grid energy of the individual time periods from Tnow to Tspecl are determined from a profile of grid energy costs over time. The number of time periods (Nlessthresh) that have a grid energy cost that is less than the cost threshold (Cthresh) is determined {block 8180) . One example of the latter determination may be as follows: Cper2Q11-2-25-1525 < Cthresh?

[2043 The amount of grid energy used at the current value of Cthresh is compared against the additional energy required. In the embodiment presented here, this comparison is made based upon the corresponding numbers of time periods, as follows: The total length of time, Tper.lessth.resh, that grid energy is predicted to cost less than the threshold cost, Cthresh, is calculated (block 8190) . This calculation is carried out by

multiplying the length of one time period (Tper) by the number of time periods with power cost below the

threshold cost (Nlessthresh to find the total length of time, as follows : Tpe lessthresh ~ Tpe * Nlessthresh.

[205] The time required for connection to grid energy that was found in block SI 50, Tperreqgrid, is compared with the time {Tperlessthresh ) that the grid power cost is below the cost threshold Cthresh {block 8200) , If Tp r1ess hresh > Tperreqgrid {YES branch of block 8205), then the current value of the cost threshold is the optimum one. Therefore, during each time period from Tnow to Tspecl, if the present cost of grid power

(Cnowgrid) is less than the threshold cost (Cthresh) , then the central processor 310 enables charging with both grid energy and other energy sources, and otherwise

permits charging only with energy sources other than the utility grid {block 8210) . During the operation of block 8210, charging from the energy sources other than the grid is carried out by the operations 1000, 1500, 2000 and 3000 described previously, and charging from the utility grid, during those time period in which it is permitted, is carried out b enabling the operation 000,

[206J Returning to block 8205, if Tperiessthresh is not greater than Iperreqgrid (NO branch of block 8205} , then the present value of the threshold, cost Cthresh is too low, and operation returns to block 8170 for further incrementing of the threshold cost Cthresh,

[2073 The central processor 310 ensures that the EV battery pack charge level reaches the charge level

Especlev specified in the user command by or before the specified completion time specl . The central processor 310 does this whenever any one of the foregoing EV charging operations (1000, 1500, 2000, 3000, 7000 or 8000} is being performed in response to the user command, as follows: During charging of the EV b any of the foregoing operations, the central processor 310

determines the present rate at which the EV battery pack 110 is being charged and ascertains the present charge level of the EV battery 110, From this information, the central processor 310 computes the required charging time needed for the SV battery pack charge level to reach the desired level, Especlev. The central processor 310 compares the required charging time with time remaining until the specified time !spec. If the charging time exceeds the remaining time, then the central processor 310 stops the current operation and begins the maximum rate charging operation 7000 of FIG. 38.

[2083 While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may foe devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

What is claimed is:

1. A method of managing electrical energy in system for charging an electric vehicle {EV) having an SV battery, comprising:

coupling a direct current bus to plural energy sources and to a system port that is correctable to an EV charging port of said electric vehicle, said plural energy sources comprising one or more energy sources having zero energy cost and one or more energy sources having non-zero energy costs;

connecting said EV charging port to said system port;

receiving a command to charge said EV battery to a specified recharge level by a specified time;

sensing the energ levels of said energy sources and of said EV battery and sensing the present voltage of said direct current bus;

determining an amount of required energy needed for said EV battery to reach said specified recharge level ;

establishing respective priorities for respective ones of said energy sources according to selected attributes of said energy sources;

establishing discharge voltage set points for respective ones of said energy sources as a function of said respective priorities; and

comparing said present voltage of said direct current bus with each one of said discharge voltage set points, and permitting discharge of the corresponding energy source to said direct current bus if said direct current bus voltage is less than the corresponding one discharge voltage set point.

2. The method of Claim 1 wherein said attributes comprise cost of energy of each energy source and energy available from each energy source, said method further comp ising :

if available energy of a combination of said energy sources having zero energy cost is adequate to meet said required energy, permitting discharge from said combination of energy sources having zero energy cost.

3. The method of Claim 2 further comprising:

wherein said establishing discharge voltage set points comprises establishing discharge voltage set points of energy sources having non-zero energy costs in inverse relation to their energy costs;

if available energy of a combination of said energy sources having zero energy cost is not adequate to furnish said additional energy, discharging respective ones of said energy sources having non-zero energy costs to said direct current bus whenever said voltage of said direct current bus is less than the corresponding

discharge voltage set point,

4. The method of Claim 2 wherein said energy sources having zero energy cost comprise at least one of a solar cell arra and a wind generator, and said energy sources having non-zero energy costs comprise at least one of a utility grid and a local energy storage unit,

5. The method of Claim 4 further comprising:

if (a.) available energy of a combination of said energy sources having zero energy cost is not adequate to furnish said required energy, and (b) energy cost of energy stored in said local energy storage unit is less than energy cost of said utility grid, then enabling discharge of said iocai energy storage unit to said direct current bus while preventing energy flow from said utility grid to said direct current bus.

6. The method of Claim 4 further comprising, if (k) cost, of energy of said utility grid is less than cost of energy stored in said local energy storage unit, or (B) energy from said local energy storage unit is not adequate to furnish said required energy, then (C) enabling a constant discharqe of the local energy storage device to the direct current bus and enabling energy flow from said utility grid to said direct current bus only during time periods in which utility grid energy cost is below a threshold cost.

7. The method of CIains 6 further comprising:

if energy from said local energy storage unit is not adequate to furnish said required energy, and if energy cost of said local energy storage unit is less than energy cost of said utility grid, adjusting the discharge voltage set point for said local energy storage unit to a value higher than a discharge voltage set point for said utility grid before performing the enabling step of <C} .

8. The method of Claim 7 further comprising:

if energy from said iocai energy storage unit is not adequate to furnish said required, energy, and if energy cost of said local energy storage unit is not less than energy cost of said utility grid, adjusting the discharge voltage set point for said local energy storage unit to be equal to a discharge voltage set point for said utility grid, before performing the enabling step of (C> ,

9. The method of Claim 6 further comprising searching for a value for said cost threshold at which the energy cost of said grid is below said cost threshold for a sufficient amount of time to obtain said required energy from a combination of said energy sources.

10, The method of Claim 9 wherein said searching for a value for said cost threshold comprises;

determining a required amount of time needed for said utility grid to furnish sufficient energy so that a combination of energy sources including said utility grid can famish said required energy;

initializing said cost threshold, to equal the minimum energy cost occurring between the present time and the specified time;

from a profile of ut lity grid energy costs, ascertaining the net amount of time that said utility grid energy costs are less than a current value of said cost threshold;

if said net amount of time exceeds said required amount of time, fixing said threshold cost at is current value; and

if said net amount of time does not exceed said- required amount of time, incrementing the current value of said cost threshold and then repeating said ascertaining step and one of said fixing or incrementing steps .

11. The method of Claim 1 further comprising:

prior to receiving said command, maintaining said EV battery at a long term storage charge level that is in a range of 40%-65% of battery capacity.

12. The method of Claim 1 wherein said permitting discharge of the corresponding energy source comprises permitting zero current flow while the bus voltage

exceeds said corresponding discharge voltage set point and permitting maximum current flow while said bus voltage is less than said discharge voltage set point.

13. The method of Claim 12 further comprising providing a ramped transition between said zero current flow and said maximum current flow over a limited bus voltage range centered around said corresponding one voltage set point_*

14. The method of Claim 1 further comprising:

carrying out said comparing and permitting steps for each one of said energy sources in a local processor dedicated to the one energy source;

carrying out said establishing discharge voltage set points i a central processor in

communication with each local processor, and

communicating the corresponding voltage set point to the corresponding local processor.

The method of Claim 1 further comprising establishing an EV recharge voltage set point for recharging said EV battery;

comparing said EV recharge voltage set point with the voltage of said direct current bus;

permitting recharging of said EV battery from said direct current bus if said bus voltage exceeds said recharge voltage set point,

16. The method of Claim 1 further comprising:

establishing an LESU recharge voltage set point for recharging said local energy storage unit;

comparing said LESU recharge voltage set point with the voltage of said direct current bus;

permitting recharging of said local energy storage unit from said direct current bus if said bus voltage exceeds said LESU recharge voltage set point.

17. The method of Claim 15 farther comprising:

establ shing a EV discharge voltage set point for discharging said EV battery to said direct current bus;

comparing said EV discharge voltage set point with the voltage of said direct current bus;

permitting discharge of said EV battery to said direct current bus if said bus voltage is less than said EV discharge voltage set point.

18. The method of Claim 1 further comprising::

establishing a utility grid energy return voltage set point for selling energ through said utility comparing said utility grid energy return

voltage set point with the voltage of said direct current bus; and

permitting current flow from said direct current bus to said utility grid if said bus voltage exceeds said utility grid energy return voltage set point .

19. The method of Claim 1 wherein said direct current bus is coupled to said utility grid through a local AC distribution panel, said method further

comprising :

establishing an AC panel backup voltage set point for flowing current f om said direct current bus to an AC distribution panel;

disconnecting a local AC panel from said utility grid in the event of a utility grid failure;

comparing said AC panel backup voltage set point with the voltage of said, direct current bus; and permitting current flow from said direct current bus to said AC utility panel if said bus voltage exceeds said AC panel backup voltage set point. The method of Claim 19 further comprising converting current flow from said direct current bus to said local AC panel from direct current to alternating current.

20. The method of Claim 19 further comprising converting current flow from said direct current bus to said local AC panel from direct current to alternating cu rent .

21. The method of Claim 1 further comprising: sensing a rate at which said EV battery is being charged, sensing a current charge level of saia EV battery pack and compnting a predicted charge completion ime;

if said charge completion tirae is after said specified time, then performing a maximum rate charging operation by discharging ail of said energy sources to said, direct current bus,

22. A modular electrical power management system for charging an electric vehicle (EV) from plural energy sources , said EV having an EV battery and an EV charging port, said system comprising :

a DC bus;

a control signal link;

a central processor coupled to said control signal link;

plural modules connected in parallel to said DC bus, each of said modules comprising a connection

terminal, the connection terminal of one of said modules being coupleable to said EV charging port , the connection terminals of the remaining ones of said modules being co piable to corresponding ones of said energy sources, each of said modules further comprising:

a DC converter coupled through said connection terminal to the corresponding energy source and coupled to said direct current bus;

a local processor connected to said DC converter and coupled to said control signal link; and a memory coupled to said local processor.

23, T e system of Claim 22 wherein said local

processor is programmed to cause said DC converter to enable current flow from the corresponding energy source whenever a voltage of said DC bus is less than a voltage set point stored in said memory, and said central

processor is programmed to provide said voltage set point via said command signal link,

24, The system oh Claim 22 wherein:

said DC bus comprises a pair of conductors; each of said modules further comprises a shunt capacitor connected to said pair of conductors,

25, The system of Claim 22 wherein said plural energy sources comprise one or more energy sources having zero energy costs and one or more energy sources having non-zero energy costs,

26, The system of Claim 22 wherein said plural energy sources comprise at least one of a solar cell- array and a wind, generator, and at least one of a utility grid and a local energy storage unit,

27, For use in a modular electrical power

management system for charging an electric vehicle (EV) from plural energy sources, said EV having an EV battery and an EV charging port from a DC bus, a module

comprising :

a conductor path for connection to said DC bus; a terminal for connection to one of said energy sources ; a control signal link connection;

a DC converter coupled between said termina and said direct current bus;

a local processor connected to said DC converter and coupled to said control signal link; an

a memory coupled to said local processor.

28. The system of Claim 27 wherein said local processor is programmed to cause said DC converter to enable current flow whenever a voltage of said DC bus is less than a voltage set point stored in said memory.

29. The system of Claim 27 wherein:

said conductor path comprises a pair of

conductors ;

said module further comprises a shunt capacitor connected to said pair of conductors.

30. An energy management system for charging an electric vehicle (EV) having an EV charging port, comprising :

a direct current (DC) bus;

plural connector ports, one of said plural connector ports connectable to said EV charging port, remaining ones of said plural connector ports connectable to respective ones of plural energy sources;

respective DC converter stages coupled between respective ones of said plural connector ports and said direct current bus;

respective local processors controlling

respective ones of said converter stages and respective memories connected to said respective local processors; and

a central processor and a command signal link connecting said central processor to said local

rocessors .

31. The system of Ciaires 30 wherein each local processor is programmed to cause the corresponding DC converter to enable current flow from the corresponding energy source to said DC bus whenever a voltage of said DC bus is less than a voltage set point stored in the corresponding memory, and said, central processor is programmed to provide said voltage set point to said corresponding memory via said command signal link.

32, The system of Claim 30 wherein :

said DC bus comprises a pair of conductors,, said DC bus comprising a main DC bus and respective DC bus branches connected to respective ones of said DC converters;

respective shunt capacitors located at boundaries between said respective DC bus branches and said m in DC bus, each of said shunt capacitors connected to said pair of conductors.

33. The system of Claim 30 wherein s id plural energy sources comprise one or more energy sources having zero energy costs and one or more energy sources having non-zero energy costs.

34, T e system of Claim 30 wherein said plural energy sources comprise at least one of a solar ceil array and a wind generator, and at least one of a uti grid and a local energy storage unit .

35, The system of Claim 34 wherein said DC

converters comprise D /DC converters connected to energy sources providing DC voltage, and at least one AC/DC converter connected to an energy source providing an AC voltag .

36. The system of Claim 30 wherein:

the DC converter stages coupled to said remaining ones of said plural connector ports comprise respective discharge terminals, said system further comprising respective diodes connected between said respective discharge terminals and said DC bus in a polarity in which each diode is forward biased for current flow from the respective DC converter stage to the DC bus; and

the respective local processors are programmed to control the respective DC stages to maintain voltages f the respective discharge terminals at respective voltage set points.

37. The system of Claim 36 wherein:

the one DC converter stage coupled to said one connector port connectabie to said EV charging port comprises a charging terminal, said system farther comprising a diode connected between said charging terminal and said DC bus in a polarity in which said diode is forward biased for current flow to the one DC converter stage from the DC bus; and the one local processor controlling said one converter stage is programmed to control the one DC converter stage to maintain voltage of said charging terminal at a selected voltage set point.

38. The system of Claim 37 wherein said central processor is programmed to provide respective voltage set points to respective ones of said local processors.