HK1196184A - High voltage energy harvesting and conversion renewable energy utility size electric power systems and visual monitoring and control systems - Google Patents

Description

High voltage energy harvesting and renewable energy conversion utility scale power system and visual monitoring and control system therefor

Technical Field

The present application relates generally to renewable energy utility size power systems and more particularly to a high voltage energy harvesting and conversion renewable energy collection and conversion system and visual monitoring and control system for the system that employs a direct current-to-direct current (DC-DC) converter.

Background

The term "renewable energy power system" as used herein refers to a solar power plant or power station formed using a plurality of interconnected photovoltaic modules, or a utility-scale power system of a wind power plant or power station formed using a plurality of interconnected wind turbine generators.

Utility-scale (output capacity from the 5-100 megawatt (MWe) range) solar photovoltaic power systems include a large number of solar photovoltaic power collectors, such as solar photovoltaic modules, that provide Direct Current (DC) power to a parallel direct current-to-alternating current (DC-AC) inverter that converts the DC power to Alternating Current (AC) power.

A utility scale wind power system includes a large number of electrically interconnected wind turbine generators. The wind turbine driven generator assembly may be a wind turbine with its output shaft suitably coupled to an electrical generator. Various types of generator systems may be coupled to the wind turbine. One such system is generally known as an industry-specified type 4 wind turbine generator power system, wherein the generator is a permanent magnet synchronous generator with a variable frequency, variable voltage output provided to a rectifier, the rectifier rectified output DC link being provided to a DC-DC inverter. The inverter output current is then converted by a line transformer, which converts the inverter output voltage level to a grid voltage level.

For utility-scale power systems, whether solar or wind-powered, renewable energy, the power system components are significantly more spread over land than conventional residential or commercial-scale power plants, making the physical visualization and control of the power system challenging beyond the typical single-line centralized control board for conventional-scale power plants.

It is an object of the present invention to provide a monitoring and control system for a high voltage renewable energy harvesting network in combination with a centralized grid-tied multiphase regulated current source inverter system, wherein the renewable energy samples can be distributively power optimized by incorporating DC-DC converters in the harvesting network.

It is another object of the present invention to provide high voltage energy harvesting in combination with a centralized grid-tied multiphase regulated current source inverter system, and a visual monitoring and control system for a utility scale renewable energy system.

It is another object of the present invention to provide an electrical energy collection, conversion, monitoring and control system for a renewable energy utility-scale electrical power system that includes a three-dimensional visually oriented virtual reality display environment (a three-dimensional, visual-oriented visual display environment) for centralized input-output control and monitoring of the electrical power system by a system operator.

Disclosure of Invention

One aspect of the invention is a renewable energy utility size electric power system. The system is provided with a high-voltage recyclable energy collection network and a centralized grid-connected multiphase regulated current source inverter system. The high voltage renewable energy harvesting network has multiple rows (multiple strings) of renewable energy collectors, each row having a DC output and a plurality of renewable energy power optimizers (power optimizers) distributed over the harvesting network. Each renewable energy power optimizer has at least one power optimizer input connected to an energy collector row of at least one of the plurality of rows of renewable energy collectors. Each of the plurality of renewable energy power optimizers and transmitters has a high voltage DC output connected to the system DC link. A plurality of renewable energy power optimizers and transmitters are arranged in a group (area distributed in combination) that provides a single positive high voltage (positive high voltage) DC output and a single negative high voltage (negative high voltage) DC output to the system DC link with a single neutral (single electrical neutral) connected to an electrical ground (electrical ground) of the system DC link. A concentrated grid-tie multiphase regulated current source inverter system is connected to the system DC link and has a plurality of grid-tie inverter package modules that can be connected to a high voltage electrical grid.

Another aspect of the invention is a renewable energy utility size electric power system. The system has a high voltage recoverable acquisition network; a centralized grid-connected multiphase regulated current source inverter system; and a virtual immersive system and central control system for monitoring and controlling the high voltage recoverable acquisition network and the centralized grid-connected multiphase regulated current source inverter system. The high voltage renewable energy harvesting network has a plurality of rows of renewable energy collectors, each row having a DC output, and a plurality of renewable energy power optimizers and transmitters. Each of the plurality of renewable energy power optimizers and transmitters has at least one row power optimizer input connected to the DC output of at least one row of the plurality of rows of renewable energy collectors. A plurality of renewable energy power optimizers and transmitters are arranged in a group that provides a single positive high voltage DC output and a single negative high voltage DC output to the system DC link with a single neutral connected to the electrical ground of the system DC link. A concentrated grid-tie multiphase regulated current source inverter system is connected to the system DC link and has a plurality of grid-tie inverter package modules.

Another aspect of the invention is a method of harvesting, converting, monitoring and controlling renewable energy from a utility scale renewable energy system. The renewable energy source comprises a high voltage renewable energy harvesting network. The harvesting network includes a plurality of rows of renewable energy harvesters, each of the plurality of renewable energy harvesters having a DC output. The harvesting network also includes a plurality of renewable energy power optimizers and transmitters. Each of the plurality of renewable energy power optimizers and transmitters has at least one row power optimizer input connected to the DC output of at least one row of the plurality of rows of renewable energy collectors. A plurality of renewable energy power optimizers and transmitters are arranged in a group that provides a single positive high voltage DC output and a single negative high voltage DC output to the system DC link with a single neutral connected to the electrical ground of the system DC link. The renewable energy system also includes a concentrated grid-tied multiphase regulated current source inverter system connected to the system DC link and having a plurality of grid-tied inverter package modules. In the present invention, virtual immersive surveillance of a high voltage renewable energy harvesting network is performed in a three dimensional visually oriented virtual reality display environment and the high voltage renewable energy harvesting network and the centralized grid-tied multiphase regulated current source inverter system are centrally controlled by communicating with the three dimensional visually oriented virtual reality display environment.

The above and other aspects of the invention are further set out in the description and claims.

Drawings

For the purpose of illustrating the invention, there is shown in the drawings a form that is presently preferred; it should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities described.

FIG. 1 is a simplified single line block diagram of one embodiment of a renewable energy utility-sized power system for collecting and converting solar energy and a monitoring and control system of the present invention for use in a power system.

FIG. 2(a) is an illustration of one embodiment of a solar power optimizer and transmitter that can be used in the present invention.

Fig. 2(b) is an illustration of another embodiment of a solar power optimizer and transmitter that can be used in the present invention.

Fig. 3(a) is an illustration of one embodiment of a resonant DC-DC converter that may be used with the solar power optimizer and transmitter shown in fig. 2 (a).

FIG. 3(b) is an illustration of one embodiment of a resonant DC-DC converter that may be used with the solar power optimizer and transmitter shown in FIG. 2 (b).

Fig. 4 illustrates a waveform in which the converter current of the resonant DC-DC converter shown in fig. 3(a) and 3(b) approaches resonance when the photovoltaic row voltage connected to the DC-DC converter is low.

Fig. 5 illustrates a waveform in which the converter current of the resonant DC-DC converter shown in fig. 3(a) and 3(b) is off-resonance when the photovoltaic row voltage connected to the DC-DC converter is high.

Fig. 6 shows an embodiment of the interconnection between a solar photovoltaic module of a solar power plant and a solar power optimizer and transmitter for use in the present invention.

FIG. 7 is a simplified black and white rendering of a three-dimensional visual display in the three-dimensional visually-oriented virtual reality display environment of the present invention.

FIG. 8 is a simplified single line block diagram of one embodiment of a renewable energy utility size power system for harvesting and converting wind energy and a monitoring and control system of the present invention for use with the power system.

Detailed Description

FIG. 1 is a simplified single line block diagram of one embodiment of a renewable energy utility-sized power system for collecting and converting solar energy and a monitoring and control system of the present invention for use in a power system. In this embodiment, there is a high voltage solar photovoltaic energy collection (also referred to as "harvesting") network 12; a centralized grid-connected multiphase synchronous regulation current source inverter system 14; and an optional virtual immersive monitoring and control system 16. The boost converter 18 isolates the output of the inverters in the grid-tie inverter packaging modules (grips) 14a-14d from the high voltage grid.

High voltage solar photovoltaic energy collection networks and centralized grid-connected multiphase synchronous regulated current source inverter systems are further described in U.S. patent No. 8,130,518.

The virtual immersion monitoring and control system includes a virtual immersion device watchdog (WIEW) module 16a and a central control module 16 b.

Fig. 2 illustrates one embodiment of a Solar Power Optimizer and Transmitter (SPOT) that may be used in the high voltage solar photovoltaic energy collection network 12 of fig. 1. The SPOT in fig. 2(a) includes a plurality of DC-DC converters 20a (4 in the present embodiment); a processor 20b (described as a microprocessor (μ P) in the present embodiment); and a transceiver 20c (described in this embodiment as a radio frequency RF transceiver with transmit and receive antennas 20 c').

The 4 DC-DC converters in fig. 2(a) convert the variable photovoltaic "row" voltage and current to a parallel fixed high voltage (e.g., 1250 volts DC). In this embodiment, the positive (+) outputs of two converters are connected in parallel and the negative (-) outputs of the two other converters are connected in parallel, as shown in fig. 2 (a). The remaining 4 outputs of these 4 converters are connected together in common as shown in fig. 2(a) to form a common (neutral) circuit. The parallel positive and negative outputs of the converters are connected (clamped) in series to a system DC link (shown in fig. 1 and 2(a) as a DC link bus 22) at a high DC voltage (e.g., 2.5kV DC) that is twice the output voltage of each DC-DC converter (e.g., 1.25kV DC). Referring to the single row block diagram of fig. 1, wherein a plurality of solar power optimizers and transmitters (as shown in fig. 2 (a)) may be connected to a plurality of solar photovoltaic modules 30. Thus, the combination of 4 DC-DC converters in fig. 2(a) can be described as a first pair of converters on the right side of the figure and a second pair of converters on the left side of the figure, with the positive outputs of the first pair of converters connected to form a single positive high voltage DC output; the negative outputs of the second pair of converters are connected to form a single negative high voltage DC output; and the positive output connections of the first pair of converters together with the negative output connections of the second pair of converters form a single neutral connection connected to a common end of the system DC link. In other embodiments of the invention any even number of DC-DC converters may be arranged with the output terminals interconnected to obtain a single positive high voltage DC output and a single negative high voltage DC output having a single neutral connection to the system DC link similar to the 4 DC-DC converter embodiment.

Fig. 3(a) is an illustrative embodiment of a DC-DC converter that may be used in the solar power optimizer and transmitter 20 in fig. 2 (a). Each DC-DC converter consists of two parts: a series resonant full bridge inverter 20 a' (shown in this embodiment as semiconductor switching devices Q1-Q4), and a combined output section 20a ″ of a filter and a single rectifier. The two parts are isolated from each other by a high frequency (range of 10kHz to 20 kHz) transformer Tx. The power drawn from the input of the photovoltaic row source on terminals 1 and 2 varies with the inverter operating frequency. The input current (Idc) and the power source (E) are measured by a processor 20b in fig. 2(a) that adjusts the operating frequency of the inverter so that the DC-DC converter operates at a maximum power point value (maximum power point value). The operating frequency of the input inverter of the converter varies around resonance, which is defined by the values of the inductor Ltank and the capacitor Ctank forming a series resonant loop in fig. 3 (a). As the frequency approaches the resonance point, the inverter draws more current from the input photovoltaic row, causing the photovoltaic row voltage to drop. As described further below, one function of the processor 20b is to maintain the mathematical results of the photovoltaic row voltage and current at the maximum power point value. Fig. 4 shows the inverter output current when approaching resonance when the input photovoltaic row voltage is low, and fig. 5 shows the inverter output current when not resonant when the input photovoltaic row voltage is high.

The processor 20b may be a microprocessor in communication with an I/O device that senses the row voltage and current at the input of each DC-DC converter 20 a. The processor runs voltage and current at the input of each converter and controls the operation of each converter by executing computer code with a Maximum Power Point Tracking (MPPT) algorithm to harvest maximum power from each row of solar photovoltaic modules. For example, the algorithm may include a "disturbance observation" subroutine by which the operating frequency of the DC-DC converter may be slightly shifted, and the MPPT algorithm decides whether to increase or decrease the collected power as the frequency is disturbed.

If a transceiver 20c is employed in a particular embodiment of the present invention, the transceiver 20c transmits power system data to the immersive monitoring and control system. The power system data may include: a row voltage amount; the amount of the row current; an amount of line power; SPOT output current magnitude; SPOT operating temperature and SPOT operating state data, such as whether the SPOT is operating at full maximum input power from all input photovoltaic rows or is operating at limited input power from at least some of the input photovoltaic rows. The transceiver 20c receives power system data including power system limit command data and power system on/off status or control. For example, the power-on or power-off state of the power system may be determined by detecting whether a particular DC-DC converter is in an operational, oscillating state (the power system is in a power-on state). Power on or off commands (from the central control module) for the remote power system may be used to facilitate maintenance of the SPOT. One method of transmitting and receiving by the transceiver 20c is through a mesh radio system (mesh radio system).

Fig. 2(b) shows an alternative Solar Power Optimizer and Transmitter (SPOT) for use in some embodiments of the high voltage solar photovoltaic energy collection network 12 of fig. 1. The SPOT25 in fig. 2(b) includes a plurality of dual rectifier DC-DC converters 25a (4 in this embodiment); a processor 20b (described as a microprocessor (μ P) in the present embodiment); and a transceiver 20c (described in this embodiment as a radio frequency RF transceiver with transmit and receive antennas 20 c').

The 4 dual rectifier DC-DC converter in fig. 2(b) converts the variable photovoltaic "row" voltage and current to a parallel fixed high voltage (e.g., 1250 volt DC). In this embodiment the 4 positive (+) outputs of the converters are connected together in parallel to form a connection to the positive DC link and the 4 negative (-) outputs of the converters are connected together in parallel to form a connection to the negative DC link, as shown in fig. 2 (b). As shown in fig. 2(b), the remaining eight outputs of the 4 converters are connected together in COMMON to form a COMMON connection to the neutral line (COMMON). The parallel positive and negative outputs of the converters are connected (clamped) in parallel to a system DC link (shown in fig. 1 and 2(b) as a DC link bus 22) at a high DC voltage (e.g., 2.5kV DC) that is twice the output voltage of each DC-DC converter (e.g., 1.25kV DC). Referring to the single row block diagram of fig. 1, wherein a plurality of solar power optimizers and transmitters (as shown in fig. 2 (b)) may be connected to a plurality of solar photovoltaic modules 30. Thus, the combination of 4 DC-DC converters in fig. 2(a) can be described as a combination of 4 DC-DC converters, each converter having a pair of rectifiers, one rectifier designated as the positive rectifier (REC 2) and the other rectifier designated as the negative rectifier (REC 1). The positive inputs of all the positive rectifiers are connected together to form a single positive high voltage DC output; the negative inputs of all negative rectifiers are connected together to form a single negative high voltage DC output; the positive connections of the negative rectifiers together with the negative connections of the positive rectifiers are connected together to form a single neutral connection to the common end of the system DC link. In other embodiments of the invention any even number of DC-DC converters may be arranged with the output terminals interconnected to obtain a single positive high voltage DC output and a single negative high voltage DC output having a single neutral connection to the system DC link similar to the 4 DC-DC converter embodiment.

Fig. 3(b) is an illustrative embodiment of a DC-DC converter that may be used in the solar power optimizer and transmitter 25 in fig. 2 (b). Each DC-DC converter consists of two parts: a series resonant full bridge inverter 25 a' (shown in this embodiment as semiconductor switching devices Q1-Q4), and a combined two (in multiples or pairs) output filter rectifier and filter section 25a ″. The two parts are isolated from each other by a high frequency (range of 10kHz to 20 kHz) transformer Tx. The power drawn from the input of the photovoltaic row source on terminals 1 and 2 varies with the inverter operating frequency. The input current (Idc) and the power source (E) are measured by a processor 20b in fig. 2(b), which adjusts the operating frequency of the inverter so that the DC-DC converter operates at the maximum power point value. The operating frequency of the input inverter of the converter varies around resonance, which is defined by the values of the inductor Ltank and the capacitor Ctank forming a series resonant loop in fig. 3 (b). As the frequency approaches the resonance point, the inverter draws more current from the input photovoltaic row, causing the photovoltaic row voltage to drop. As described further below, one function of the processor 20b is to maintain the mathematical results (mathematical products) of the voltage and current of the photovoltaic rows at the maximum power point value. Fig. 4 shows the inverter output current when approaching resonance when the input photovoltaic row voltage is low, and fig. 5 shows the inverter output current when not resonant when the input photovoltaic row voltage is high.

The control of the DC-DC converters utilized in fig. 2(a), 2(b), 3(a), and 3(b) may be performed by the inverter controller changing the connection frequency of the switching devices (semiconductors Q1 to Q4 in the present embodiment) of the inverter section utilized in the DC-DC converters.

Another control of the DC-DC converter may be performed by the inverter controller varying the conduction time (duration) of the switching devices of the inverter section utilized in the DC-DC converter in each cycle, while maintaining a fixed near resonant frequency (fixed near resonant frequency).

Alternatively, another control of the DC-DC converter may be performed by combining a change in the pass-through frequency and a change in the on-time (duration of the connection) of the inverter switching devices. That is, the converter control may be performed by varying the communication frequency (commutation frequency) of the inverter switching devices within one range (in a first range), and varying the on-time of the inverter switching devices within each cycle while maintaining a fixed resonance frequency within yet another range (in a second range). The variable frequency range is in the vicinity of the resonant frequency, while the fixed frequency and variable on-time of the inverter switching devices are in a range away from resonance.

The embodiment of the invention shown in fig. 2(a) and 2(b) utilizes a solar power optimizer and emitter, and each photovoltaic row 31 may include 20-25 photovoltaic modules. The output of each row is typically at 1-10 amps DC (at 400-1000 volts DC), depending on solar energy system parameters such as solar irradiance, shading, or environmental degradation. A set of 4 solar photovoltaic modules can be connected to the multiple SPOTs shown in fig. 2(a) and 2(b) to produce approximately 200 and 6250 "watts/input row" for each SPOT with 4 row inputs, with a maximum of 25000 watts.

Fig. 6 shows an embodiment of an interconnection of renewable energy utility size power systems utilizing the solar power optimizer and transmitter of the present invention. A maximum number of solar two optimizers and transmitters, for example 20, may share each SPOT "horizontal" bus 21a, 21b, 21c … 21x, as shown in fig. 6. For example, the SPOT horizontal bus 21a has 20 solar power optimizers and transmitters 21a1 to 21a20 connected to the bus. These interconnected 20 solar power optimizers and emitters and the photovoltaic modules connected to these 20 solar power optimizers and emitters comprise a photovoltaic energy harvesting array 21, which represents a part of the high voltage photovoltaic energy collection network 12 illustrated in fig. 1 and which is capable of producing a maximum of 500kW from solar radiation. The photovoltaic energy harvesting array 21 may include 4 (photovoltaic) rows of photovoltaic modules connected to each of the 20 solar power optimizers and emitters in the array 21, each photovoltaic row consisting of approximately 20-25 photovoltaic modules connected in series. The combination of 4 photovoltaic rows of photovoltaic modules can be considered a photovoltaic "bank" of about 80-100 modules, whereby a total of 1600 and 2000 photovoltaic modules are connected to the SPOT horizontal bus 21a within an array 21 of 20 solar power optimizers and combiners. Each of the other photovoltaic energy harvesting arrays including the SPOT horizontal bus 21b … 21x (where x is a variable representing the last bus and array including the photovoltaic collection network 23) may also produce a maximum of 500kW from solar radiation; figure 6 does not show the photovoltaic rows in these other arrays connected to the solar power optimizer and emitters. Each SPOT horizontal bus is connected to a SPOT "vertical" bus (26 a, 26b, 26c, … 26x in fig. 6) respectively to connect to grid-tie inverter package modules (14 a, 14b, 14c and 14 d) in the concentrated grid-tie multiphase regulated current source inverter system 14. This practical arrangement limits the conductor size forming each SPOT vertical bus to a maximum current capacity of 200 amps DC based on the photovoltaic module array connected to each solar power optimizer and emitter providing a maximum of 10 amps DC.

The central control module 16b in fig. 1 includes circuitry for communicating between the plurality of solar optimizers and transmitters and the inverter modules within the concentrated grid-tied multiphase synchronous regulated current inverter system, and for sending and receiving power system data, such as collecting data transmitted from each SPOT; preferably with the grid-tied inverter enclosure modules 14a-4b via a secure data link 17 (shown in dashed lines in fig. 1), such as secure ethernet; if a three-dimensional data-oriented virtual reality display environment is used in an embodiment of the present invention, communication with the three-dimensional data-oriented virtual reality display environment is performed, for example, via a VIEW computer system; monitoring a High Voltage (HV) grid voltage injected into the grid by the centralized inverter system; and monitoring the voltage of the DC link 22 between the acquisition system 12 and the transformation system 14; controlling the amount of set DC input current sent to each grid-tied inverter package module, wherein the amount of set DC input current is set to match the current generated by the acquisition system 12 according to the requirements of the conversion system 14; and controlling the phase of the AC current injected into the grid relative to the phase of the AC grid voltage.

In one embodiment of the present invention, the energy conversion system 14 includes a plurality of grid-tied inverter package modules. While 4 grid-tie inverter package modules 14a-14b are illustrated in the system embodiments of fig. 1 and 6, typically the total number of grid-tie inverter package modules in other system embodiments of the present invention is in the range of 3 to 40. The grid-connected inverter package module includes circuitry for: converting the inverter package power rating (2500 kW in the embodiment of fig. 1) from DC to AC; sending (reporting) grid-connected inverter package operating parameters to a central control module and a three-dimensional visually-oriented virtual reality display environment (e.g., a VIEW computer); operating parameters such as the set DC input current magnitude set point and the phase angle of the grid-tie inverter package as described in the previous paragraph are received from the central control module. The transmitted operating parameters include: a DC input current input to the grid-connected inverter package module; AC output phase currents (phase currents) from the grid-tied inverter package module; an AC output phase voltage from the grid inverter package module; AC output power from the grid inverter package module; an output frequency from the grid-connected inverter package module; the coolant (if used) temperature in the grid inverter package module cooling subsystem; and a selected grid tied inverter package circuit assembly temperature.

In one embodiment of the invention, the virtual immersive monitoring system is a three-dimensional, visually-oriented, virtual reality display environment that includes a VIEW computer system that collects acquisition system information; presenting the collected acquisition information using three-dimensional virtual reality techniques described further below; and predicting an electrical power output injected into the grid based on the effective irradiance of the solar energy recoverable system.

Fig. 7 illustrates key elements of the virtual immersive surveillance system of the present invention, fig. 7 being a simplified black and white illustration of a three dimensional image displayed in part of a high voltage solar photovoltaic energy source data network on a VIEW computer visual display unit. In this illustration, the photovoltaic modules 30 that make up the photovoltaic row are visible relative to the dynamic external environment of the installation, including, for example, the dynamic real time closed shading of the components. The relative positions of the SPOT20 or 25 are illustrated, along with the conductor 91 from the photovoltaic row connected to the input of the SPOT20 or 25, and the DC link 22 to which the output of the SPOT20 or 25 is connected. Each SPOT can be packaged in an approximately 12X6 enclosure with 4 links for the photovoltaic row inputs on the top of the enclosure as shown in fig. 7, and 3 inputs and outputs conductors (positive, negative and neutral (common) as shown in fig. 2(a) or fig. 2 (b)) passing through (except for the SPOT at the end of the SPOT horizontal bus) at the sides of the SPOT enclosure or at the bottom of the SPOT enclosure. Each photovoltaic group of photovoltaic modules may be mounted on a structural support (structural support) that may also serve as a mounting structure (under or to the side of the rack) for the solar power optimizer and emitters associated with the photovoltaic group. All color decoding elements, cloud visualization (cloud visualization), and other display elements of the immersive monitoring system described below are completed by a three-dimensional image of the power system provided by a VIEW computer visual display unit, which is an element of a three-dimensional visually-oriented virtual reality display environment.

The present invention provides two embodiments of a virtual immersive monitoring and control system for solar power. One embodiment, shown as base 31 in fig. 1, tracks the photovoltaic array with a fixed tilt and the other tracks the photovoltaic array with a dual axis. An accurate three-dimensional description of a solar power plant site is incorporated into the VIEW computer display model. The operator's VIEW of the VIEW computer display model can be provided on a suitable computer visual output device, such as a video monitor, from a virtual camera VIEW that passes unconstrained through the three-dimensional space. The operator may control the movement of the camera through three-dimensional space by means of a suitable computer input device, such as a hand-held controller, joystick or trackball. The movement may be through a photovoltaic array and optionally on a predetermined three-dimensional spatial trajectory of individual components of the solar power plant.

The power output of each photovoltaic row of the solar power plant may be displayed on a VIEW computer visual display unit. Each photovoltaic row may be referenced by SPOTs (referrals) for controlling the row and central control module having associated row SPOT communication performance parameters. The morning-to-evening shifting of the sun's rays on the solar power plant can provide varying levels of illumination to the photovoltaic modules and can affect the direction that the dual-axis tracker (if used) faces, making it always perpendicular to the direction of insolation. In one embodiment of the virtual immersive monitoring system of the present invention, the power, current, and voltage values are characterized by suitable ranges of color intensities as a function of the power, current, and voltage magnitudes associated with the power system components, such as photovoltaic modules, solar power optimizers and transmitters, interconnected electrical conductors, and switching components associated with the grid-tied inverter packaging modules, to form an image of the power system components on the VIEW computer visual display unit.

In one embodiment of the invention, the color coding of the rated output of the photovoltaic row module is done by shading (shade) of a continuous color spectrum ranging from bright blue, which represents rows running at full power, to dark blue, which is less than full power, and finally to black, which represents that the functional row produces zero power. The color conversion is linear with the rated power output. Any row that does not generate power due to a device failure is visually displayed in red to distinguish it from a normal row that generates zero power. The power system electrical conductors may be displayed green to indicate the magnitude of current passing therethrough, with light green indicating a higher current level and dark green indicating a lower current level. The conductors appear red in the event of a failure or malfunction. Each SPOT may be represented by yellow, with higher current levels represented by bright yellow and lower current levels represented by darker yellow. The SPOT shell that failed or malfunctioned is shown in red. Inverters, transformers, grid switching devices and other components may be rendered by natural color (natural color). An active meter graphic icon (such as kilowatts) may be placed at an appropriate location in a visual display (e.g., in a corner of the visual display) for displaying the real-time total electrical power generated in the appropriate unit. The operator-controllable visual display indicator icon may be used by the operator to visually display details of the power output and the energy produced by the system element with a unique identifier, such as the number of the element, in the meter image icon.

In a virtual immersive surveillance system, the cloud image(s) may be reconstructed with shadows generated by the photovoltaic panel surface. Shadows are detected by the drop-off variation of the photovoltaic electrical power collected from a portion of the solar farm.

The system may include execution of a predictive algorithm that visually displays the power output of the system near a future time (e.g., 10 minutes from now on in real time) based on cloud movement parameters (cloud direction and speed) relative to the site.

In one embodiment model of the invention, visualization may be done through dedicated visual layers on the VIEW computer visual display unit, such that different phases of the device (e.g., the built-in transparent photovoltaic module) and the highlight (highlight) power system are activated by switching on or off selected display layers.

FIG. 8 is a simplified single line block diagram of one embodiment of a renewable energy utility size power system for harvesting and converting wind energy and a monitoring and control system of the present invention for use with the power system. The variable frequency AC power generated by the permanent magnet synchronous generator is rectified by an AC-AC converter 51 and then applied to a Wind Power Optimizer and Transmitter (WPOT) 40. The wind power optimizer and transmitter apply an optimal load to the synchronous generator for operating the wind turbine at a maximum power point value. Wind power optimizers and transmitters are similar to solar power optimizers and transmitters in that they typically, but not exclusively, employ a single DC-DC converter rather than the 4 DC-DC converters (or other even number of DC-DC converters) used for solar power optimizers and transmitters as shown in fig. 2(a) or fig. 2 (b). The output of one or more wind power optimizers and transmitters are connected through a high voltage DC link 42 to a centralized grid-tied multiphase synchronous regulated current source inverter system 14 employing three or more grid-tied inverter package modules, such as the modules 14a-14b shown in fig. 8.

If a virtual immersive monitoring system is used in certain embodiments of the present invention, the virtual immersive monitoring system communicates with one or more of the wind power optimizer and transformer and the grid-tied inverter package module to visually depict the operation of the wind power plant on a VIEW computer display unit. The three-dimensional visually oriented display environment comprises a three-dimensional terrain layer (terrain layer) of a wind power plant. A universal wind generator may be used. Depending on the number of turbines, an appropriate number of grid-tie inverter packages may be selected, with each turbine having approximately 1.5MW and each grid-tie inverter package having a power rating of 2.5 Megawatts (MW). The visualization of the virtual immersive surveillance system is arranged so that the grid-tied inverter is in the foreground (forego) and the turbine and connections to the inverter system are clearly visible. The transformer may be placed beside the inverter and outside the building in which the inverter is placed. The visualization of the output of the wind turbine may be a power meter graphical icon, layered on a three-dimensional visually oriented display environment, with at least real-time power output and optionally historical data in numerical or graphical form.

The virtual immersive system elements for a solar energy system described above may also be applied to a virtual immersive system for a wind energy system unless the element specifically emphasizes that the element or function is solely for solar energy rather than wind energy.

The invention has been described in terms of preferred examples and embodiments. It is intended that all equivalents, alternatives and modifications, except those specifically mentioned, be considered within the scope of the invention.

Claims (27)

1. A renewable energy, utility-scale electric power system comprising:

a high voltage renewable energy harvesting network comprising:

a plurality of rows of renewable energy collectors, each row of the plurality of rows of renewable energy collectors having a DC output;

a plurality of renewable energy power optimizers and transmitters, each of the plurality of renewable energy power optimizers and transmitters having at least one row power optimizer input connected to the DC outputs of at least one of the plurality of rows of renewable energy collectors, each of the plurality of renewable energy power optimizers and transmitters having a high voltage DC output connected to a system DC link, each of the plurality of renewable energy power optimizers and transmitters being arranged to connect a single positive high voltage DC output and a single negative high voltage DC output to the system DC link, the system DC link having a single electrical neutral line connected to a system DC link ground line; and

a centralized grid-tied multiphase synchronous regulated current source inverter system having a plurality of grid-tied inverter package modules each having an input connected to the system DC link.

2. The renewable energy, utility-size electric power system of claim 1 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

at least one pair of DC-DC converters, each of the at least one pair of DC-DC converters having a string inverter input and a converter pair DC link output, the string inverter input connected to the at least one string power optimizer input and the converter pair DC link output connected to the high voltage DC output; and

a processor for sensing and monitoring the voltage and current of the row inverter input of each of the at least one pair of DC-DC converters, and for controlling each of the at least one pair of DC-DC converters at a maximum power point.

3. The renewable energy, utility-size electric power system of claim 1 or 2 further comprising an inverter controller for controlling the frequency of commutation of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters.

4. The renewable energy, utility-scale power system of claim 1 or 2 further comprising an inverter controller for controlling the on-time of a plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters during a cycle while maintaining a fixed near resonant frequency.

5. The renewable energy, utility-scale power system of claim 1 or 2 further comprising an inverter controller for controlling the turn-on frequency of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters in a near resonant frequency range and controlling the turn-on time of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters during a period while maintaining the fixed frequency in a non-resonant range.

6. The renewable energy, utility-size electric power system of claim 1 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

a combination of 4 DC-DC converters, each of the 4 DC-DC converters including independent first and second pairs of DC-DC converters, each of the combination of 4 DC-DC converters having a string inverter input connected to each of the at least one string power optimizer inputs, and a positive converter output and a negative converter output provided by a single rectifier, the first pair of independent DC-DC converters having a positive converter output connected in parallel to a single positive high voltage output connected to the system DC link, and the second pair of independent DC-DC converters being connected in parallel to a negative converter output of a single negative high voltage output connected to the system DC link, the negative converter outputs of the first pair of independent DC-DC converters and the positive converter output of the second pair of independent DC-DC converters being connected together in common to the single pair of DC-DC converters An electrical neutral wire.

A processor for sensing and monitoring the voltage and current of the row inverter input of each of the 4 DC-DC converters, and for controlling each of the 4 DC-DC converters at a maximum power point; and

a transceiver connected to an antenna for transmitting and receiving a plurality of high voltage renewable energy harvesting system data and a plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data.

7. The renewable energy, utility-size electric power system of claim 1 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

a combination of a plurality of DC-DC converters, each of the 4 DC-DC converters having a string inverter input connected to each of the at least one string power optimizer inputs, and a pair of rectifiers, each of the pair of rectifiers comprising a positive rectifier and a negative rectifier, the positive outputs of the positive rectifiers of the combination of 4 DC-DC converters are connected together in parallel to the single positive high voltage output, the single positive high voltage output is connected to the system DC link, the negative outputs of the negative rectifiers of the combination of 4 DC-DC converters are connected together in parallel to the single negative high voltage output, the single negative high voltage output is connected to the system DC link, and the negative output of the positive rectifier of the combination of 4 DC-DC converters and the positive output of the negative rectifier of the combination of the plurality of DC-DC converters are connected together to the single electrical neutral.

A processor for sensing and monitoring the voltage and current of the row inverter input of each of the 4 DC-DC converters, and for controlling each of the 4 DC-DC converters at a maximum power point; and

a transceiver connected to an antenna for transmitting and receiving a plurality of high voltage renewable energy harvesting system data and a plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data.

8. The renewable energy, utility-size electric power system of claim 1 or 2 further comprising:

means for communicating between the plurality of solar optimizers and transmitters and the plurality of grid inverter package modules;

the device is used for sending and receiving a plurality of high-voltage renewable energy collecting network data and a plurality of centralized grid-connected multiphase synchronous regulation current inverter system data.

9. The renewable energy, utility-size electric power system of claim 6 wherein each of the 4 DC-DC converters further comprises a variable frequency controllable resonant inverter having a resonant inverter input connected to the string inverter input and a resonant inverter output connected to an input of the single rectifier through an isolation transformer, the single rectifier having outputs connected to the positive and negative rectifier outputs, and a processor for controlling each of the 4 DC-DC converters at a maximum power point by varying an operating frequency of the variable frequency controllable resonant inverter.

10. The renewable energy, utility-scale power system of claim 7 wherein each of the 4 DC-DC converters further comprises a variable frequency controllable resonant inverter having a resonant inverter input connected to the row inverter input and a resonant inverter output connected to the input of the pair of rectifiers through an isolation transformer, and a processor for controlling each of the 4 DC-DC converters at a maximum power point by varying an operating frequency of the variable frequency controllable resonant inverter.

11. The renewable energy, utility-size electric power system of claim 1 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of wind turbine driven AC generators having rectified dc output, and each of the plurality of renewable energy power optimizers and transmitters comprises:

at least one pair of DC-DC converters, each of the at least one pair of DC-DC converters having a string inverter input and a converter pair DC link output, the string inverter input connected to the at least one string power optimizer input, and the converter pair DC link output connected to the high voltage DC output; and

a processor for sensing and monitoring the voltage and current of the row inverter input of each of the at least one pair of DC-DC converters, and for controlling each of the at least one pair of DC-DC converters at a maximum power point.

12. A method for harvesting, transforming, monitoring and controlling renewable energy using a utility scale renewable energy system, comprising: a high voltage renewable energy harvesting network comprising: a plurality of rows of renewable energy collectors, each row of the plurality of rows of renewable energy collectors having a DC output; and a centralized grid-connected multiphase synchronous regulated current source inverter system having a plurality of grid-connected inverter package modules, the method comprising the steps of optimizing the DC outputs of the plurality of rows of renewable energy collectors to a maximum power point, distributing a plurality of renewable energy power optimizers and transmitters within the high voltage renewable energy harvesting network, and having the plurality of renewable energy power optimizers and transmitters arranged to provide a single positive high voltage DC output and a single negative high voltage DC output having a single electrical neutral line, and connecting the single positive and negative high voltage DC output and the single electrical neutral line of the plurality of renewable energy power optimizers and transmitters to the centralized grid-connected multiphase synchronous regulated current source inverter system through a system DC link having a positive, a negative, and a neutral line, A negative and common bus connected to the single positive high voltage DC output, the single negative high voltage DC output and the single electrical neutral line, respectively.

13. A renewable energy, utility-scale electric power system comprising:

a high voltage renewable energy harvesting network comprising:

a plurality of rows of renewable energy collectors, each row of the plurality of rows of renewable energy collectors having a DC output;

a plurality of renewable energy power optimizers and transmitters, each of the plurality of renewable energy power optimizers and transmitters having at least one row power optimizer input connected to the DC outputs of at least one of the plurality of rows of renewable energy collectors, each of the plurality of renewable energy power optimizers and transmitters having a high voltage DC output connected to a system DC link, each of the plurality of renewable energy power optimizers and transmitters being configured to connect a single positive high voltage DC output and a single negative high voltage DC output to the system DC link, the system DC link having a single electrical neutral line connected to a ground line of the system DC link; and

a centralized grid-tied multiphase synchronous regulated current source inverter system having a plurality of grid-tied inverter package modules each having an input connected to the system DC link, an

And the virtual immersion type monitoring system and the central control system are used for monitoring and controlling the high-voltage renewable energy collection network and the centralized grid-connected multiphase synchronous regulation current source inverter system.

14. The renewable energy, utility-size electric power system of claim 13 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

at least one pair of DC-DC converters, each of the at least one pair of DC-DC converters having a string inverter input and a converter pair DC link output, the string inverter input connected to at least one string power optimizer, and the converter pair DC link output connected to the high voltage DC output; and

a processor for sensing and monitoring the voltage and current of the row inverter input of each of the at least one pair of DC-DC converters, and for controlling each of the at least one pair of DC-DC converters at a maximum power point.

15. The renewable energy, utility-size electric power system of claim 13 or 14 further comprising an inverter controller for controlling a frequency of commutation of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters.

16. The renewable energy, utility-scale electric power system of claim 13 or 14 further comprising an inverter controller for controlling the on-time of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters during the period while maintaining the fixed near resonant frequency.

17. The renewable energy, utility-scale power system of claim 13 or 14 further comprising an inverter controller for controlling the connection frequency of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters in a near resonant frequency range and controlling the conduction time of the plurality of inverter switching devices in each of the plurality of renewable energy power optimizers and transmitters during a period while maintaining the fixed frequency in a non-resonant range.

18. The renewable energy, utility-size electric power system of claim 13 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

a combination of 4 DC-DC converters, each of the 4 DC-DC converters including independent first and second pairs of DC-DC converters, each of the combination of 4 DC-DC converters having a string inverter input connected to each of the at least one string power optimizer inputs, and a positive converter output and a negative converter output provided by a single rectifier, the first pair of independent DC-DC converters having a positive converter output connected in parallel to a single positive high voltage output connected to the system DC link, and the second pair of independent DC-DC converters being connected in parallel to a negative converter output of a single negative high voltage output connected to the system DC link, the negative converter outputs of the first pair of independent DC-DC converters and the positive converter output of the second pair of independent DC-DC converters being connected together in common to the single pair of DC-DC converters An electrical neutral wire.

A processor for sensing and monitoring the voltage and current of the row inverter input of each of the 4 DC-DC converters, and for controlling each of the 4 DC-DC converters at a maximum power point; and

a transceiver connected to an antenna for sending a plurality of high voltage renewable energy collection system data and a plurality of centralized grid connected multiphase synchronous regulated current source inverter system data to the virtual immersive surveillance system and the central control system and receiving a plurality of high voltage renewable energy collection system data and a plurality of centralized grid connected multiphase synchronous regulated current source inverter system data from the virtual immersive surveillance system and the central control system.

19. The renewable energy, utility-size electric power system of claim 13 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of solar photovoltaic modules and each of the plurality of renewable energy power optimizers and transmitters comprises:

a combination of a plurality of DC-DC converters, each of the 4 DC-DC converters having a string inverter input connected to each of the at least one string power optimizer inputs, and a pair of rectifiers, each of said pair of rectifiers comprising a positive rectifier and a negative rectifier, the positive outputs of said positive rectifiers of the combination of 4 DC-DC converters being connected together in parallel to a single positive high voltage output, the positive high voltage output is connected to the system DC link, the negative outputs of the negative rectifiers of the combination of 4 DC-DC converters are connected together in parallel to a single negative high voltage output, the negative high voltage output is connected to the system DC link, and the negative output of the positive rectifier of the combination of 4 DC-DC converters and the positive output of the negative rectifier of the combination of multiple DC-DC converters are connected together to the single electrical neutral line.

A processor for sensing and monitoring the voltage and current of the row inverter input of each of the 4 DC-DC converters, and for controlling each of the 4 DC-DC converters at a maximum power point; and

a transceiver connected to an antenna for sending a plurality of high voltage renewable energy collection system data and a plurality of centralized grid connected multiphase synchronous regulated current source inverter system data to the virtual immersive surveillance system and the central control system and receiving a plurality of high voltage renewable energy collection system data and a plurality of centralized grid connected multiphase synchronous regulated current source inverter system data from the virtual immersive surveillance system and the central control system.

20. The renewable energy, utility-size electric power system of claim 13 or 14 further comprising:

means for communicating between the plurality of solar optimizers and transmitters and the plurality of grid inverter package modules;

means for transmitting and receiving a plurality of high voltage renewable energy collection network data and a plurality of centralized grid connected multiphase synchronous regulated current inverter system data;

means for communicating with the virtual immersive monitoring system.

21. The renewable energy, utility-size electric power system of claim 13 or 14 wherein the virtual immersion monitoring system comprises a virtual immersion device watchdog computer system for collecting a plurality of high voltage renewable energy harvesting system data and a plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data; the system comprises a plurality of high-voltage renewable energy collection system data and a plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data which are visually displayed in a three-dimensional visual-oriented virtual reality environment; and for predicting an electrical power output from the high voltage renewable energy harvesting network for injection into a high voltage electrical grid based on the effective radiation of the plurality of rows of renewable energy collectors.

22. The renewable energy, utility-size electric power system of claim 18 wherein each of the 4 DC-DC converters further comprises a variable frequency controllable resonant inverter having a resonant inverter input connected to the string inverter input and a resonant inverter output connected to an input of the single rectifier through an isolation transformer, the single rectifier having outputs connected to the positive and negative rectifier outputs, and the processor is configured to control each of the 4 DC-DC converters at a maximum power point by varying an operating frequency of the variable frequency controllable resonant inverter.

23. The renewable energy, utility-size electric power system of claim 19 wherein each of the 4 DC-DC converters further comprises a variable frequency controllable resonant inverter having a resonant inverter input connected to the string inverter input and a resonant inverter output connected to the input of the pair of rectifiers through an isolation transformer, and the processor is configured to control each of the 4 DC-DC converters at a maximum power point by varying an operating frequency of the variable frequency controllable resonant inverter.

24. The renewable energy, utility-scale power system of claim 13 wherein each of the plurality of rows of renewable energy collectors comprises a plurality of wind turbine driven AC generators having rectified dc output, and each of the plurality of renewable energy power optimizers and transmitters comprises:

at least one pair of DC-DC converters, each of the at least one pair of DC-DC converters having a string inverter input and a converter pair DC link output, the string inverter input connected to the at least one string power optimizer input, and the converter pair DC link output connected to the high voltage DC output; and

a processor for sensing and monitoring the voltage and current of the row inverter input of each of the at least one DC-DC converter, and for controlling each of the at least one DC-DC converter at a maximum power point.

25. The renewable energy, utility-scale electric power system of claim 13 wherein the virtual immersion monitoring system comprises a virtual immersion device watchdog computer system for collecting a plurality of high voltage renewable energy collection system data and a plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data; and the system is used for visually displaying the plurality of high-voltage renewable energy collection system data and the plurality of centralized grid-connected multiphase synchronous regulated current source inverter system data in a three-dimensional visual-oriented virtual reality environment.

26. The renewable energy, utility-scale electric power system of claim 24 wherein each of the at least two DC-DC converters further comprises a variable frequency controllable resonant inverter having a resonant inverter input connected to each of the at least one row inverter inputs and a resonant inverter output connected through an isolation transformer to an input of a single rectifier having outputs connected to the positive and negative rectifier outputs, and the processor is for controlling each of the at least one DC-DC converters at a maximum power point by varying an operating frequency of the variable frequency controllable resonant inverter.

27. A method for harvesting, transforming, monitoring and controlling renewable energy using a utility scale renewable energy system, comprising: a high voltage renewable energy harvesting network comprising: a plurality of rows of renewable energy collectors, each row of the plurality of rows of renewable energy collectors having a DC output; and a plurality of renewable energy power optimizers and transmitters, each of the plurality of renewable energy power optimizers and transmitters having at least one row power optimizer input connected to the DC output of at least one of the plurality of rows of renewable energy collectors, each of the plurality of renewable energy power optimizers and transmitters having a high voltage DC output connected to a system DC link, and the plurality of renewable energy power optimizers and transmitters being arranged to provide a single positive high voltage DC output and a single negative high voltage DC output having a single neutral, and the single positive high voltage DC output, the single negative high voltage DC output and the single electrical neutral being connected to positive, negative and common buses of the system DC link; the centralized grid-connected multiphase synchronous regulating current source inverter system is provided with a plurality of grid-connected inverter packaging modules; the method comprises the following steps of monitoring the high-voltage renewable energy collection network in a three-dimensional visual-oriented virtual reality environment in a virtual immersion mode, and controlling the high-voltage renewable energy collection network and the centralized grid-connected multiphase synchronous regulation current source inverter system to be communicated with the three-dimensional visual-oriented virtual reality environment in a central mode.