VIRTUAL INVERTER FOR POWER GENERATION UNITS

• US 20140306533A1
• Filed: 04/11/2013
• Published: 10/16/2014
• Est. Priority Date: 04/11/2013
• Status: Active Grant

• Current Assignee: Solantro Semiconductor Corp. (China Electronics Corporation)
• Original Assignee: Solantro Semiconductor Corp. (China Electronics Corporation)
• Inventors: PAQUIN, Antoine Marc Joseph Richard, KEYES, Edward Patrick, ORR, Raymond Kenneth, PRESTON-THOMAS, Peter Giles, CHAPEL, Olivier Anne Jean-Yves
• Granted Patent: US 9,755,430 B2
• Time in Patent Office: Days
• US Class Current: 307/52
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A gateway controller allows a plurality of individual power generation units coupled to an electrical distribution grid to be controlled in a coordinated fashion. The gateway controller allows control of the plurality of individual power generation units as a single power generation unit. The gateway controller may determine required control parameters of the power generation units that will provide a desired combined behavior, such as combined alternating current injected into the grid, and issues commands to the power generation units based on the determined control parameters.

Claims

1. A photovoltaic (PV) power generation and control system comprising:

a coordinated power generation group comprising a plurality of generation units capable of outputting alternating current (AC), each generation unit comprising;

a PV panel capable of producing direct current (DC); and

an inverter capable of outputting AC from the DC produced by the PV panel, the inverter including a communication interface for receiving remote control information for setting at least one control parameter to control an output characteristic of the inverter; and

a gateway controller comprising;

a communication interface for communicating with the respective inverters of the plurality of generation units; and

control functionality for determining remote control information for setting respective control parameters of the inverters of the plurality of generation units to cooperatively control the output characteristics of the inverters of the plurality of power generation units to provide a desired combined behaviour from the plurality of power generation units.

2. The system of claim 1, wherein the control functionality of the gateway controller comprises islanding functionality for controlling the output of the inverters to cooperatively detect islanding of the coordinated power generation group.

3. The system of claim 2, wherein the islanding functionality sets control parameters of the inverters to cease injecting power into the electrical grid when islanding is detected.

4. The system of claim 3, wherein the control functionality further comprises islanding recovery functionality for detecting that the coordinated power generation group is no longer in a power island and for resuming power injection into the electrical grid.

5. The system of claim 1, wherein the control functionality of the gateway controller comprises output power control functionality for adjusting the output of respective inverters to provide a desired combined output from the coordinated power generation group.

6. The system of claim 5, wherein the output power control functionality determines the output of the respective inverters to extend an expected lifetime of at least one of the plurality of inverters.

7. The system of claim 5, wherein the output power control functionality determines the output of the respective inverters using one or more of:

naï

ve power reduction;

degradation leveling;

hours of operation;

cumulative power production;

partial power reduction;

uniform power reduction;

power leveling;

power maintenance;

temperature leveling;

or

temperature maintenance.

8. The system of claim 1, wherein the control functionality of the gateway controller comprises grid stability and safety control functionality.

9. The system of claim 8, wherein the grid stability and safety control functionality comprises one or more of:

over voltage/over frequency functionality;

disconnect functionality;

spinning reserve functionality;

reactive power functionality;

reactive power leveling functionality;

reactive power optimization functionality; and

fault ride through functionality.

10. The system of claim 1, wherein the coordinated power generation group further comprises:

a connection point for coupling the inverters of the plurality of power generation units to an electrical grid, the connection point comprises a monitoring component for monitoring one or more characteristics of the AC injected into the electrical grid.

11. The system of claim 10, wherein the monitoring component of the connection point further monitors one or more characteristics of the AC of the electrical grid.

12. The system of claim 10, further comprising a plurality of coordinated power generation groups, each having a respective connection point.

13. The system of claim 1, wherein the inverter further comprises a temperature sensor for measuring a temperature of the inverter, and

wherein the controller of the inverter further comprises functionality capable of monitoring the temperature measured by the temperature sensor and communicating the monitored temperature to the gateway controller.

14. The system of claim 1, wherein the inverter further comprises a voltmeter for measuring a voltage of the AC output from the inverter, and

wherein the controller of the inverter further comprises functionality capable of monitoring the voltage of the AC output measured by the voltmeter and communicating the monitored voltage to the gateway controller.

15. The system of claim 14, wherein the inverter further comprises an ammeter for measuring a current of the AC output from the inverter, and

wherein the controller of the inverter further comprises functionality capable of monitoring the current of the AC output measured by the ammeter and communicating the monitored current to the gateway controller.

16. A gateway controller for controlling a plurality of power generation units each outputting alternating current (AC) to an electrical distribution grid, the gateway controller comprising:

a communication interface for communicating with the plurality of power generation units; and

at least one processor and associated memory storing instructions for execution by the at least one processor, when executed by the processor, the instructions configuring the gateway controller to;

determine a desired combined behaviour from the plurality of power generation units;

determine control parameters of individual power generation units required to provide the desired combined behaviour; and

issue commands, using the communication interface, to the individual power generation units to control the determined control parameters of the individual power generation units to provide the desired combined behaviour from the plurality of power generation units.

17. The gateway controller of claim 16, wherein the instructions, when executed by the processor, further configure the gateway controller to:

control the output of the power generation units to cooperatively detect islanding of the plurality of power generation units.

18. The gateway controller of claim 16, wherein the instructions, when executed by the processor, further configure the gateway controller to:

issue commands to the individual power generation units to cease injecting power into the electrical grid when islanding is detected.

19. The gateway controller of claim 18, wherein the instructions, when executed by the processor, further configure the gateway controller to:

determine that the plurality of power generation units are no longer in a power island; and

issue commands to the power generation units to resume power injection into the electrical distribution grid.

20. The gateway controller of claim 16, wherein the desired combined behavior is providing a desired combined output power to the electrical distribution grid, and the issued commands comprise commands for adjusting output of respective power generation units to provide the desired combined output from the plurality of power generation units.

21. The gateway controller of claim 20, wherein the output power of the respective power generation units are adjusted to extend an expected lifetime of at least one of the plurality of power generation units.

22. The gateway controller of claim 20, wherein the output of the individual power generation units required to provide the desired combined output is determined using one or more of:

naï

ve power reduction;

degradation leveling;

hours of operation;

cumulative power production;

partial power reduction;

uniform power reduction;

power leveling;

power maintenance;

temperature leveling;

or

temperature maintenance.

23. The gateway controller of claim 16, wherein the desired combined behavior provides grid stability and safety control functionality.

24. The gateway controller of claim 23, wherein the grid stability and safety control functionality comprises one or more of:

over voltage/over frequency functionality;

disconnect functionality;

spinning reserve functionality;

reactive power functionality;

reactive power leveling functionality;

reactive power optimization functionality; and

fault ride through functionality.

25. A method controlling a plurality of power generation units, each outputting alternating current (AC) to an electrical distribution grid, the method comprising:

determining at a gateway controller a desired combined behaviour from the plurality of power generation units;

determining control parameters of individual power generation units required to provide the desired combined behaviour; and

issuing commands, using a communication interface of the gateway controller, to the individual power generation units based on the determined control parameters of the individual inverters to provide the desired combined behaviour from the plurality of power generation units.