HK1170341A - Enclosure housing electronic components having hybrid hvac/r system with power back-up - Google Patents

Description

Housing containing electronic components with hybrid HVAC/R system with power backup

Technical Field

The invention relates to a housing that houses electronic components having a hybrid HVAC/R system with a backup power source.

Background

Telecommunication enclosures or housings are often located in remote locations. These shields are typically cooled by field-powered air conditioning systems that maintain the internal temperature below a temperature that causes the telecommunications system to shut down, otherwise malfunction, or jeopardize reliable operation. Enclosures for other electronic equipment, such as military applications, sentry bases or federal emergency administration equipment locations, housing electronic components that are temperature sensitive for military, monitoring, inspection or other applications, may also be located where access to power from the grid is limited or even unavailable.

Where grid power is not available or is unreliable, the alternating current may be provided by a generator. However, if ac power is lost, there is not enough, timely backup of power, and if the temperature within the enclosure rises above a certain threshold, the temperature sensitive system may cease to operate. This can lead to significant damage to sensitive computer equipment.

Although battery backup systems are provided for many applications, such backups are typically used only to operate electronic or telecommunications equipment and may not provide sufficient power for air conditioning systems due to limited battery power output.

Disclosure of Invention

The enclosure or housing of the electronic equipment may include a heating, ventilation, air conditioning and refrigeration (HVAC/R) system having a power backup and configured to maintain an environment within the enclosure or housing. The power backup may provide sufficient power for continued operation of the HVAC/R system when the primary power source is unavailable.

In one embodiment, a shroud containing temperature sensitive electronic components and an HVAC/R system that controls the temperature within the shroud, the shroud comprising: an Alternating Current (AC) power source; an HVAC/R system including one or more three-phase motors and one or more single-phase motors; a Direct Current (DC) power supply including a rechargeable battery assembly, the power supply configured to provide power to the HVAC/R system when sufficient AC power is not available from the AC power source; and a Variable Frequency Drive (VFD) configured to provide three-phase power to the one or more three-phase motors and single-phase power to the one or more single-phase motors.

In another embodiment, an enclosure for housing electronic components and an air conditioning system, comprises: an air conditioning system including a compressor, a variable speed compressor engine, and one or more evaporators; an AC power source; a DC power source including a rechargeable battery assembly, the power source configured to provide power to the air conditioning system when sufficient AC power is not available from the AC power source; a VFD providing three-phase power to the variable speed compressor motor; and a pulsed-state operating refrigerant flow control valve configured to control refrigerant flow to the one or more evaporators.

In another embodiment, an HVAC/R system includes: one or more three-phase motors; one or more single phase motors; an alternator; a DC power source including a rechargeable battery assembly, the power source configured to provide power to the HVAC/R system when sufficient AC power is not available; and a VFD power supply electrically connected to the DC power source and configured to provide three-phase power to the three-phase motor and single-phase power to the single-phase motor.

In a further embodiment, an HVAC/R power supply system includes: an AC power source connected to the rectifier to provide DC power to the DC power bus; a DC power source connected to the DC power bus; a VFD configured to receive DC power and output AC power to at least one AC motor in the HVAC/R system; and a VFD controller electrically connected to the VFD, the controller configured to control an output frequency of the VFD to control a speed of the AC motor.

In another embodiment, a method for controlling an HVAC/R power supply system includes: receiving data indicative of a capacity of an AC power source; receiving data indicative of a capacity of a DC power source; receiving data indicative of an electrical load of the HVAC/R system; commanding the VFD controller to draw power from the DC power source if the AC power source capacity is less than the electrical load of the HVAC/R system; and commanding the VFD controller to reduce the load of the HVAC/R system if the load of the HVAC/R system is greater than the combined AC power source capacity and DC power source capacity.

Drawings

FIG. 1 is a perspective view of a telecommunications shroud with a top and some sidewalls removed to show an interior cavity and generally showing an air conditioning and treatment system;

FIG. 2 is a schematic block diagram illustrating an embodiment of an HVAC/R power supply system with a rechargeable DC power source backup;

FIG. 3 is a schematic diagram illustrating an embodiment of an integrated rectifier;

FIG. 4 is a schematic diagram illustrating an embodiment of a power boost unit;

FIG. 5 is a schematic diagram of elements of an HVAC/R system including a pulse control valve;

FIG. 6 is a schematic block diagram illustrating an embodiment of an HVAC/R power supply system with a rechargeable DC power backup that utilizes an AC generator as the AC power source; and

FIG. 7 is a flow chart illustrating exemplary logic for a controller (e.g., a power supply controller).

Detailed Description

One embodiment relates to a housing that houses sensitive electronic equipment, such as telecommunications equipment. The enclosure uses a heating, ventilation, air conditioning and refrigeration (HVAC/R) system to control the temperature within the enclosure so that the electronic equipment is not damaged by exposure to high temperatures. In this embodiment, the HVAC/R system is normally powered by Alternating Current (AC) and is also connected to a Direct Current (DC) power source that can provide power when sufficient AC power is not available. To most efficiently provide cooling to the enclosure, the HVAC/R system is operated using one or more three-phase motors and one or more single-phase motors. To maintain efficiency, Variable Frequency Drives (VFDs) that provide three-phase power to a three-phase motor and single-phase power to a single-phase motor may be used within HVAC/R systems. In one embodiment, the AC power is first converted to DC power to power the VFD.

Three-phase motors, such as compressor motors in HVAC/R systems, can be operated much more efficiently and with less wear if their electrical characteristics of operation are controllable. For example, in one embodiment, when starting a three-phase motor, the frequency of the drive power may be adjusted to avoid transient current spikes and unnecessary wear on the motor. A plurality of Variable Frequency Drives (VFDs) are capable of receiving DC power and outputting regulated (e.g., frequency controlled) AC power to a plurality of motors. By varying the frequency of the power to the motor, the VFD can more effectively control the speed of the motor. The system described herein may utilize a VFD in an HVAC/R system to improve the efficiency of the system by providing control over the speed and output of HVAC/R system components. For example, if the controlled temperature environment requires some cooling, it may be more efficient to run the HVAC/R system components (e.g., the compressor engine) at a reduced speed to meet the actual demand, rather than running it at full speed. Being able to adjust the speed of HVAC/R components such as those mentioned above also prevents unnecessary cycling of the system and allows finer control of the environment as a whole.

Due to the variety of different HVAC/R system components and their individual power requirements, it is often more advantageous to provide more than one VFD in an HVAC/R system. Further, a VFD controller may be provided to collectively control the plurality of VFDs to maximize HVAC/R system performance and efficiency.

Conventional AC power sources, such as AC grid power, may be unreliable depending on where the power supply needs, weather, and other variables. Thus, one embodiment is a shroud that uses an HVAC/R power supply system that can provide uninterrupted power to HVAC/R system components regardless of the condition of the AC power source. Embodiments thus include a DC power source, such as a battery, that stores power and may be used to control the VFD when AC power is not available from the AC power source. In another embodiment, a DC power source may be used to supplement the power available to the HVAC/R system when, for example, the AC power source is from a generator of limited output capacity. In such systems, the DC power source may be used to provide supplemental power during periods of increased electrical load or to provide power during periods when the AC power generator is unavailable.

Another embodiment relates to a system using a power supply controller that allows an HVAC/R system to selectively draw power from a plurality of individual power supplies. The power supply controller, which may be stand alone or incorporated into the VFD controller, may improve overall system efficiency by precisely controlling the power supply for the HVAC/R components when multiple power supplies are available.

Accordingly, one embodiment relates to providing power to an HVAC/R system, which may include AC and DC power sources having different electrical characteristics and configured to provide uninterrupted power to HVAC/R system components in many environments. In this embodiment, the system reliably and efficiently maintains the internal environment of various types of enclosures that may contain sensitive electronic equipment, thus ensuring optimal operation of the electronic equipment.

Fig. 1 is a perspective view of a telecommunications shroud 100 with the top and some sidewalls removed to show the interior cavity and generally showing the air conditioning and handling system. Within the telecommunications shroud 100 is a vertical rack 150 having shelves configured to support various types of electronic equipment, such as telecommunications equipment. The environment of the telecommunications shroud 100 is controlled by a heating, ventilation, air conditioning and refrigeration (HVAC/R) system. The HVAC/R system may include components such as a condenser unit 135, a refrigeration circuit 120, an air handling unit 115, a primary air channel 110, and a secondary air channel 105. Additional HVAC/R components will be discussed more fully with reference to FIG. 3. The components of the HVAC/R system are used to control the environment within the shroud 100, including, for example, temperature and humidity. Additional description of air treatment embodiments may be found in U.S. patent application No.11/941,839, filed on 16.11.2007, which is incorporated herein by reference in its entirety. In addition, the shroud is provided with a connection to an AC power source 130, for example to a public AC grid power source.

To provide uninterrupted power to the HVAC/R system, power is provided to the HVAC/R system through a power supply unit 125, the power supply unit 125 including a Direct Current (DC) power supply 140. The DC power source 140 may be, for example, one or more DC batteries. In other embodiments, the DC power source 140 is housed in the power supply unit 125 housing. Preferably, the DC power source 140 is rechargeable. In the embodiment of FIG. 1, if the AC power source 130 becomes unavailable, the power supply unit 125 may instead provide power to the HVAC/R system from the capacity stored in the DC power source 140. Thus, the HVAC/R system maintains the environment within the telecommunications shroud 100 regardless of whether the AC power source 130 is immediately available.

FIG. 2 is a schematic block diagram illustrating an embodiment of an HVAC/R power system 200 with a rechargeable DC power backup and components of the HVAC/R system. The AC power source 130 is supplied with AC power from, for example, an AC grid power source. The AC power source 130 is electrically connected to the rectifier 215. A rectifier is an electrical device that converts AC power that periodically changes direction to DC power where current flows in only one direction. The rectifier may be fabricated from solid state diodes, vacuum diodes, mercury arc valves, and other components known in the art. In some embodiments, rectifier 215 includes a combined transformer that is capable of transforming an AC input voltage from, for example, AC power source 130. The rectifier embodiment with the combined transformer will be described in more detail later in connection with fig. 3. In a preferred embodiment, a filter 275 (or smoothing circuit) is electrically connected to the output of the rectifier to draw a smooth DC current from the rectified AC power source 130. There are many existing methods of smoothing the DC current including, for example, electrically connecting a storage capacitor or smoothing capacitor to the DC output of rectifier 215. The filter 275 is also electrically connected to the DC power bus 210 to provide filtered DC power to other HVAC/R power supply system 200 components.

The DC power bus 210 is electrically connected to the components of the HVAC/R power system 200 to provide power to those components. The DC power bus 210 may include one or more conductors, such as wires or cables, capable of conducting and carrying power. The DC power bus 210 may be an interwoven plurality of wires with physical connectors so that the bus may be connected to components and expanded to meet the power requirements of the HVAC/R power supply system 200. Some embodiments of the DC power bus may include sub-buses at different voltages, such as a high voltage DC sub-bus and a low voltage DC sub-bus. In this manner, a single DC power bus may provide DC power at different voltage levels depending on the needs of the components connected to the DC power bus 210 and the voltages of the various power sources connected to the system. In this embodiment, the DC power bus 210 is electrically connected to the DC power source 220 so that it can be recharged. The DC power source 220 may be, for example, a battery or a plurality of batteries electrically connected to each other. If multiple batteries are used, they may be connected in series or parallel to produce a composite voltage that is different from the voltage of a single battery cell. To limit the amount of charging current flowing to the DC power source 220, a current limiting circuit or battery charge controller 280 may be provided between the power bus 210 and the DC power source 220. The charge controller 280 limits the current that charges the DC power supply 220 according to the specification of the DC power supply 220 so that the DC power supply 220 is not damaged at the time of charging. In addition, the battery charge controller 280 may adjust the DC power supply 220 for longer lasting operation.

The DC power source 220 may include one or more batteries, such as an automobile battery. Typically, such batteries have a relatively low voltage, such as 12 volts or 24 volts. Although batteries may be connected in series to increase the voltage, a DC power supply 220 with fewer batteries or a lower voltage is preferred. Accordingly, the DC power supply 220 may be connected to the power boost unit 240. The boosted voltage may be obtained by DC-to-DC conversion using a DC-to-AC inverter. A DC to AC inverter is an electrical device that converts DC power to AC power. The transformed AC current may be at any voltage and frequency, using suitable transformers, switches and control circuitry, as is well known in the art. Inverters are commonly used to provide AC power from a DC source such as a solar panel or battery. In fig. 2, the DC power supply 220 is a low voltage power supply, such as a 12 volt car battery. The DC power source 220 is electrically connected to a power boost unit 240 that includes a DC to AC inverter 225. The inverter 225 converts the low voltage current from the DC power source 220 to a higher voltage output AC current. Power boost unit 240 also includes rectifier 235. The inverter 225 is electrically connected to a rectifier 235 that converts the high voltage AC current back to DC current, but at a voltage higher than the voltage of the original DC power source 220. For example, 12 volts of current from DC power source 220 is converted to 300 volts of DC current with power boost unit 240. An embodiment of the power boost unit is further described below with reference to fig. 4. A power boost unit 240 is also connected to the DC power bus 210 to provide high voltage DC power for HVAC/R system components. The same process may also be used to step down the voltage of the DC power supply 220, where, for example, the DC power supply is a high voltage source and requires low voltage DC. The process of reducing the voltage is the same except that the step of inverting the DC current to AC will reduce rather than increase the voltage of the supplied current.

AC power may also be selectively stepped up or down using a transformer, which is a device that transfers electrical energy from one circuit to another circuit over an inductively coupled conductor. The varying current in the first or primary conductor produces a varying magnetic flux in the core of the transformer and, therefore, a varying magnetic field through the secondary conductor. The changing magnetic field induces a voltage in the secondary conductor. If a load is connected to the secondary conductor, current will flow in the secondary conductor and electrical energy will be transferred from the primary circuit to the load through the transformer. By appropriately selecting the turns ratio of each conductor, the transformer can selectively step up or step down the AC voltage.

The DC power bus 210 is also electrically connected to a Variable Frequency Drive (VFD) controller 265. The VFD controller 265 is electrically connected to the plurality of VFDs 230, and includes electronics that provide power and control signals to the VFDs 230, for example, to turn them on or off or to adjust their drive frequency during operation. The VFD controller 265 may receive signals from sensors (not shown), such as temperature sensors, installed in the telecommunication shroud 100 and may include logic to control the VFD 230. In other embodiments, the VFD controller 265 may include a stationary control panel (not shown) mounted in a remote location, such as in the telecommunications shroud 100, for manually controlling the plurality of VFDs. The VFD controller 265 may also monitor the current load on the power bus 210 and vary the current draw of the VFD (230a and 230b) to avoid any dangerous over-current conditions. In an alternative embodiment, the VFD controller 265 may require AC power so it may be electrically connected to an inverter (not shown) fed by the power bus 210 in order to receive AC operating power. In another embodiment, the VFD may provide AC power to a controller that requires AC operating power. In further embodiments, the VFD controller may receive AC power directly from the AC power source 130. The VFD controller 265 may include a microprocessor or computing system including software and hardware configured to accomplish the foregoing operations.

Each VFD controls the speed of the AC motor, e.g., compressor motor 250 and blower 270. As is well known in the art, VFDs control the speed of the engine by controlling the frequency of the electrical power supplied to the engine. Variable frequency drives are sometimes alternatively referred to as Adjustable Frequency Drives (AFDs), Variable Speed Drives (VSDs), AC drives, microdrives or inverter drives. These are sometimes referred to as VVVF (variable voltage variable frequency) drives because the voltage varies with frequency. In the embodiment shown in FIG. 2, multiple VFDs (230a and 230b) are electrically connected to separate components of the HVAC/R system. Since different elements of the HVAC/R system, such as the compressor motor 250 and the blower 270, may have different operating requirements, such as optimal speed and current draw, it is convenient to provide multiple VFDs based on the system needs; however, multiple VFDs are not necessary. Further, multiple VFDs are preferred because they can vary the speed of different engine components depending on the HVAC/R system needs. For example, when the HVAC/R system is in a cooling mode, wherein the cooling demand is minimal, the plurality of VFDs may reduce the speed of the blower 270 and reduce the speed of the compressor motor 250 to accommodate the reduced cooling demand. This advantageously reduces not only the overall power consumption, but also reduces unnecessary wear on HVAC/R system components. The VFD, such as VFD 230a, may also be electrically connected to a phase change module 255, which is electrically connected to another HVAC/R component, such as a condenser fan 260. In this embodiment, the condenser fan 260 has a single phase motor that is incompatible with the multi-phase output of the VFD 230a that is required by the compressor motor 250 on the same circuit. However, since the compressor motor 250 and the condenser fan 260 are typically operated simultaneously, it is convenient to provide current to both via the VFD 230 a. The phase change module 255 converts the multi-phase VFD output current into a single phase current to effectively operate the condenser fan 260. In some embodiments, the phase change module 255 may include a plurality of series capacitors and at least one capacitor in parallel with the plurality of series capacitors. In other embodiments, multiple VFDs are electrically connected to the DC power bus 210 and individually controlled, for example, by a local control panel, without the need for the VFD controller 265.

Fig. 3 is a schematic diagram illustrating an embodiment of an integrated rectifier 300. Rectifier 300 includes a combined transformer 305, rectifier circuit 310 and filter 315. In this embodiment, the rectifier 300 can receive a 230 volt AC signal and a 110 volt AC signal and is configured to produce a 30 volt DC output signal. The low voltage DC signal may be used to charge a DC power source (not shown). Accordingly, in some embodiments, a rectifier, such as rectifier 300, may be directly electrically connected to a DC power source, such as a battery, so that the low voltage DC output can charge the DC power source. The transformer 305 comprises 3 taps 320 and 322 at the input side. To generate a 110 volt AC signal, the two taps at the top, 320 and 321, are electrically connected to transformer 305. Alternatively, to generate a 230 volt AC signal, the two outermost taps, 320 and 322, are electrically connected to transformer 305. Transformer 305 steps down the input voltage to produce a lower output voltage for rectifier circuit 310. In this embodiment, the rectifying circuit 310 is a four diode bridge rectifier. Other rectifier configurations may also be used. The filter 315 then smoothes the DC output signal from the rectifier circuit 310. As shown in fig. 3, filter 315 is a single capacitor. In other embodiments, alternative filters known in the art may be used.

Fig. 4 is a schematic diagram illustrating an embodiment of a power boost unit, such as power boost unit 240 in fig. 2. Power boost unit 400 includes two 12-volt DC to 120-volt AC inverters 410 and 411, rectifiers 415 and 416, and filter 420. The power boost unit 400 receives a 24 volt DC power signal from a DC power source 405, such as a battery or series of batteries, and outputs 300 volt DC power. Each inverter 410 and 411 is configured to receive a 12 volt DC input and output a 120 volt AC signal. Rectifiers 415 and 416 both rectify the corresponding AC signal, producing a DC output of about 150 volts. Rectifiers 415 and 416 are connected in series and thus together produce a combined DC signal of about 300 volts. In the embodiment shown in fig. 4, rectifiers 415 and 416 are each four diode bridge rectifiers connected in parallel with a capacitor. Other rectifier configurations may also be used. Additionally, a filter 420 is connected across the rectifier output. The filter 420 is configured to improve the quality of the DC output signal. As shown in fig. 4, filter 420 is a single capacitor. In other embodiments, alternative filters may be used.

FIG. 5 is a schematic diagram of the elements of an HVAC/R system 500 including a pulse control valve 510. Refrigerant circulates through the system through a refrigerant line 120. The compressor motor 250 compresses the refrigerant circulating in the refrigeration line 120 and then transfers it to the condenser 505, where the compressed refrigerant is cooled and liquefied. The condenser fan 260 helps cool the compressed refrigerant by forcing air over cooling fins (not shown) attached to the condenser 505. The compressor motor 250 is electrically connected to the VFD 230, which provides three-phase AC power to the compressor motor. The VFD 230 is also electrically connected to a phase change module 255 that converts the three-phase AC power to single-phase AC power for the condenser fan 260. Collectively, the compressor motor 250, condenser 505, condenser fan 260 and phase change module 255 comprise the condenser unit 135 of fig. 1. After the refrigerant is cooled and condensed in the condenser unit 135, it is delivered to the pulse control valve 310.

A pulse control valve 510 controls the flow of refrigerant from the condenser 505 to the evaporator 515. Conventional evaporators are designed to operate at full refrigerant flow and are inefficient at low flow rates, and fluctuating flow rates. However, VFD powered compressor motors 250 may result in variable refrigerant flow to the condenser and evaporator as the drive frequency is adjusted according to system cooling needs. For optimal system performance, the pulse control valve 510 is used to produce the optimal refrigerant flow rate regardless of the VFD 230 action. This refrigerant control is particularly important at the lower refrigerant flow rates produced by variable compressor speeds. The pulse control valve 510 may be a mechanical valve such as described in U.S. patent nos. 5,675,982 and 6,843,064, or an electrically operated valve such as described in U.S. patent No.5,718,125, the descriptions of which are incorporated herein by reference in their entirety.

The evaporator 515 evaporates the compressed refrigerant, thereby extracting heat from the air surrounding it. The evaporator 515 may additionally have metal fins (not shown) to increase its heat exchange efficiency.

FIG. 6 is a schematic block diagram illustrating an embodiment of an HVAC/R power supply system 600 with a rechargeable DC power backup that utilizes an AC generator 605 as the AC power source. Fig. 6 is the system of fig. 2 with the addition of additional sensors 610 and 615 and an additional controller 620. In addition, the power supply unit 625 in fig. 6 is supplied with AC power by the AC power generator 605, not by the AC grid power supply.

The AC power generator 605 is an electrical device that converts mechanical energy into electrical energy. An AC power generator is typically a portable device having a fuel-fired engine for rotating generator components and producing electrical energy. The generator may output single or multi-phase AC power at a variety of voltages and wattages. For example, a portable diesel generator may have a three-phase, 460 volt, AC output with a maximum rated output of 10 kilowatts. Other generators may be capable of outputting single-phase and multi-phase currents at different voltages and simultaneously. Other embodiments of AC generators are well known in the art.

AC capacity sensor 610 is electrically connected to AC power generator 605. The AC capacity sensor may be either of an active sensing type, which operates by sensing the instantaneous power output of the generator and calculating the remaining capacity of the generator; or may be of a passive type whereby the generator sends a signal corresponding to its remaining power output capacity to the AC capacity sensor. In addition, other sensing methods as are known in the art may also be used. Useful switching and sensing components and circuits are described in U.S. patent No.7,227,749, which is incorporated herein by reference. The AC capacity sensor 610 is also electrically connected to a power supply controller 620, which will be described in more detail below.

The DC capacity sensor 615 is electrically connected to the DC power source 220. The DC capacity sensor may be either an active sensing type, which operates by sensing the instantaneous capacity of the DC power supply; or may be of a passive type whereby DC power source 220 sends a signal corresponding to its remaining power output capacity to DC capacity sensor 615. For DC power sources, such as batteries, the power source capacity is typically based on the instantaneous voltage of the power source. For example, as the measured voltage across the battery terminals decreases, the calculated DC power supply capacity also decreases. However, other sensing methods as are known in the art may also be used. In addition, DC capacity sensor 615 is also electrically connected to a power supply controller 620, which will be described in more detail below.

Power supply controller 620 is electrically connected to one or more power capacity sensors, such as AC capacity sensor 610 and DC capacity sensor 615. In this embodiment, the power controller 620 is also electrically connected to the VFD controller 265. The power controller 620 receives power output capacity data from the sensors connected thereto, as well as power load data from the VFD controller, and calculates the power distribution. In a simple embodiment, the power controller 620 may command the VFD controller 265 to select the AC power generator 605 as the power source or to select the DC power source 220 as the power source to operate the HVAC/R components. In a preferred embodiment, the power supply controller 620 senses the load required by the VFD controller and commands the VFD controller to selectively draw supplemental power from the DC power source, but relies primarily on the AC power generator 605 so as not to overload the AC power generator 605. For example, during startup of the HVAC/R components, the power demand will temporarily exceed the total power output of the AC power generator 605, or exceed the instantaneous power capacity of the AC power generator 605. In this case, the power supply controller 620 would instruct the VFD controller 265 to take advantage of the capacity stored in the DC power supply 220 to avoid generator overload and potential HVAC/R component damage. Similarly, given the combined capacity of the DC power source 220 and the AC power generator 605, the power source controller 620 may command the VFD controller 265 to reduce its power draw. In a preferred embodiment, the power controller 620 may cause the VFD controller 265 to draw power from any available power source, such as the AC power generator 605 and the DC power source 220, at any incremental value (e.g., 0% -100%). It should be noted that in other embodiments, there may be additional power sources, such as AC grid power, in addition to the AC power generator 605. Similarly, depending on the programming of power controller 620, there may be multiple independent DC power sources to draw independently.

In other embodiments, the power controller 620 may be incorporated into the VFD controller 265. In such an embodiment, the VFD controller can receive data from the AC capacity sensor 610 and the DC capacity sensor 615 so that it regulates the power drawn from each power source according to the load required by the HVAC/R system.

The power controller 620 may include a microprocessor or computing system including software and hardware configured to accomplish the foregoing operations. Examples of controller features and functions are described in U.S. patent No.7,630,856, the relevant portions of which are incorporated herein by reference.

FIG. 7 is a flow diagram illustrating exemplary logic for a controller, such as power controller 620 in FIG. 6. In the embodiment of fig. 7, the power supply controller is AC biased; that is, where sufficient AC power is available, the controller will preferably always draw from an AC power source, such as AC power generator 605 in fig. 6, rather than from a DC power source, such as DC power source 220 in fig. 6. Such a strategy is not required, but may be preferred, where it is desirable to keep the DC power supply at maximum capacity as much as possible. Additionally, it may be desirable to reduce cycling (i.e., charge-discharge-charge) of the DC power supply to extend the useful life of the DC power supply. Accordingly, at state 705, power controller 620 receives capacity data from an AC capacity sensor, such as sensor 610 in FIG. 6. Then, at state 710, power controller 620 receives capacity data from a DC capacity sensor, such as sensor 615 in FIG. 6. Then, at state 715, the power supply controller receives load data from a VFD controller, such as controller 265 in FIG. 6. The power controller 620 then compares the current load to the available AC capacity at decision step 720. If the load is less than the AC capacity, power controller 620 determines if it is drawing from the DC power source in decision state 750. If drawing from a DC power source, the power supply controller 620 commands the VFD to draw power only from the AC power source in state 755 because there is sufficient AC capacity. On the other hand, if power is not being drawn from the DC power source, the power supply controller returns to the data collection step at state 705. If at decision state 720, the load is greater than the AC capacity that can be provided alone, then the power supply controller determines at decision state 725 whether the load is greater than the combined capacity of the AC and DC power supplies. If the combined power capacity of the AC and DC power sources is sufficient to cover the load, the power supply controller commands the VFD controller to draw additional power from the DC power source in state 745. On the other hand, if the load is greater than the combined power capacity of the AC and DC power sources, the power controller 620 determines whether there is remaining DC capacity at decision state 730. If there is remaining DC capacity at decision state 730, the power controller 620 commands the VFD controller to draw the remaining DC power capacity from the DC power source at state 745, and then the power controller returns to the data collection step at state 705. If there is no remaining DC power capacity at the decision state 730, the power supply controller commands the VFD controller to reduce the power drawn at state 735. For example, in state 735, the power controller may command the VFD controller to reduce the speed of all motors attached to the VFD to reduce the total power drawn. The power controller then returns to the data collection step at state 705. FIG. 7 is merely one exemplary embodiment of programming logic that may be used with power controller 620.

While the above detailed description has shown, described, and pointed out novel features as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the devices and processes illustrated may be made by those skilled in the art without departing from the spirit of the invention. As will be recognized, the present invention may be embodied within a form that does not provide all of the features and benefits set forth herein, as some features may be used or practiced separately from others.

Claims (35)

1. An enclosure including temperature sensitive electronic components and a heating, ventilation, air conditioning and refrigeration (HVAC/R) system for controlling temperature within the enclosure, the enclosure comprising:

an Alternating Current (AC) power source;

an HVAC/R system including one or more three-phase motors and one or more single-phase motors;

a Direct Current (DC) power supply including a rechargeable battery assembly, the power supply configured to provide power to the HVAC/R system when sufficient AC power is not available from the AC power source; and

a Variable Frequency Drive (VFD) configured to provide three-phase power to the one or more three-phase motors and single-phase power to the one or more single-phase motors.

2. The enclosure of claim 1, wherein each of the one or more three-phase motors drives a compressor.

3. The enclosure of claim 2, further comprising an electronic controller linked to the VFD and configured to control an output of the VFD.

4. The enclosure of claim 2, further comprising at least one condenser, at least one evaporator, and conduits leading refrigerant from the compressor to the at least one condenser and from the at least one condenser to the at least one evaporator, and a pulse-mode operating refrigerant flow control valve connected to said conduits for controlling the flow of refrigerant to the one or more evaporators.

5. The enclosure of claim 4, wherein the pulsed operation refrigerant flow control valve is a mechanical valve.

6. The enclosure of claim 4, wherein the pulsed operation refrigerant flow control valve is an electronic valve.

7. The enclosure of claim 1, wherein the single phase motor drives a condenser fan.

8. The enclosure of claim 1, further comprising a phase change module connected between the VFD and the one or more single phase motors, the phase change module comprising a plurality of series capacitors and at least one capacitor connected in parallel with the plurality of series capacitors.

9. The enclosure of claim 1, further comprising a phase change module configured to condition a three-phase power output for input to a single-phase motor.

10. The enclosure of claim 9, wherein the phase change module comprises a plurality of series capacitors.

11. The enclosure of claim 1, further comprising an AC power generator for providing AC power, a first sensor for monitoring a capacity of the AC power generator, a second sensor for monitoring a capacity of the DC power source, and a controller in communication with the first and second sensors, the VFD power supply, the controller configured to regulate power supplied to the VFD in response to the sensed capacities of the AC power generator and the DC power source being at a level that avoids overloading the system.

12. The enclosure of claim 1, wherein the electronic component comprises a telecommunications device.

13. An enclosure for housing electronic components and an air conditioning system, comprising:

an air conditioning system including a condenser, a variable speed condenser engine, and one or more evaporators;

an Alternating Current (AC) power source;

a Direct Current (DC) power supply including a rechargeable battery assembly, the power supply being configured to provide power to the air conditioning system when sufficient alternating current is not available from the AC power source;

a Variable Frequency Drive (VFD) configured to provide three-phase power to the variable speed condenser motor; and

a pulsed operation refrigerant flow control valve configured to control refrigerant flow to the one or more evaporators.

14. The enclosure or shield of claim 13 wherein the pulsed operation refrigerant flow control valve is a mechanical valve.

15. The enclosure or shield of claim 13 wherein the pulsed operation refrigerant flow control valve is an electronic valve.

16. The enclosure or shroud of claim 13, wherein the VFD is configured to also provide single phase power to a single phase motor.

17. The enclosure or shroud of claim 16, wherein the single phase motor is a condenser fan motor.

18. The enclosure or shroud of claim 13, further comprising an electronic controller electrically connected to the VFD for controlling the VFD output.

19. The enclosure or shield of claim 18 wherein the electronic controller is further linked to a pulsed state operating cryogen flow control valve for controlling the flow of cryogen within the enclosure or shield.

20. The enclosure of claim 13, further comprising an AC power generator for providing AC power, a first sensor for monitoring a capacity of the AC power generator, a second sensor for monitoring a capacity of the DC power source, and a controller in communication with the first and second sensors, the VFD power supply, the controller configured to regulate power supplied to the VFD in response to the sensed capacities of the AC power generator and the DC power source being at a level that avoids overloading the system.

21. A heating, ventilation, air conditioning and refrigeration (HVAC/R) system comprising:

one or more three-phase motors;

one or more single phase motors;

an Alternating Current (AC) power generator;

a Direct Current (DC) power source including a rechargeable battery assembly, the power source configured to provide power to the HVAC/R system when sufficient AC power is not available; and

a Variable Frequency Drive (VFD) power supply electrically connected to the DC power source and configured to provide three-phase power to the three-phase motor and single-phase power to the single-phase motor.

22. The HVAC/R system of claim 21, further comprising a sensor for monitoring the available capacity of the AC power generator.

23. The HVAC/R system of claim 22, further comprising a sensor for monitoring the available capacity of the DC power source, and wherein the controller is configured to switch between the AC and DC power supplied to the VFD in response to the sensed AC power generator and DC power source capacity.

24. An HVAC/R power supply system comprising:

an Alternating Current (AC) power source connected to the rectifier for providing Direct Current (DC) power to the DC power bus;

a Direct Current (DC) power source connected to the DC power bus;

a Variable Frequency Drive (VFD) configured to receive DC power and output AC power to at least one AC motor in the HVAC/R system; and

a VFD controller electrically connected to the VFD and configured to control an output frequency of the VFD to control a speed of the AC motor.

25. The HVAC/R power supply system of claim 24, wherein the AC power source is an AC grid power source.

26. The HVAC/R power supply system of claim 24, wherein the AC power source is an AC generator.

27. The HVAC/R power supply system of claim 24, wherein the DC power source is a battery.

28. The HVAC/R power supply system of claim 24, wherein the VFD controller is a microprocessor.

29. The HVAC/R power supply system of claim 24, further comprising a power supply controller electrically connected to the VFD controller, the power supply controller configured to adjust power consumption of the VFD controller with respect to the AC power source and the DC power source.

30. The HVAC/R power supply system of claim 29, further comprising an AC capacity sensor configured to sense AC power capacity, and a DC capacity sensor configured to sense DC power capacity.

31. The HVAC/R power supply system of claim 24, further comprising:

a charge controller electrically connected to the DC power source and configured to regulate a charging current to the DC power source.

32. The HVAC/R power supply system of claim 24, further comprising:

a filter electrically connected to the rectifier configured to filter the rectified DC power output from the rectifier.

33. The HVAC/R power supply system of claim 24, further comprising a power boost unit configured to receive an input voltage and output an output voltage, wherein the output voltage is greater than the input voltage.

34. A method for controlling an HVAC/R power supply system, the method comprising:

receiving data indicative of a capacity of an Alternating Current (AC) power source;

receiving data indicative of a capacity of a Direct Current (DC) power source;

receiving data indicative of an electrical load of the HVAC/R system;

commanding a Variable Frequency Drive (VFD) controller to draw power from a DC power source if the AC power source capacity is less than an electrical load of the HVAC/R system; and is

If the load of the HVAC/R system is greater than the combined AC power source capacity and DC power source capacity, the VFD controller is commanded to reduce the load of the HVAC/R system.

35. The method of claim 32, further comprising:

commanding the VFD controller to draw power only from the AC power source when a load of the HVAC/R system is less than the AC power source capacity and the VFD controller is drawing power from the DC power source.