Virtual synchronous generator system and method with virtual inertia control

Patent metadata

Field	Value
Publication number	US-10749446-B2
Application number	US-201916238516-A
Country	US
Kind code	B2
Filing date	Jan 2, 2019
Priority date	Jan 2, 2019
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A virtual synchronous generator device disclosed. The device includes an inverter and inverter controller having a power control portion, a power reserve portion, a power point tracking control portion, and a virtual inertia control portion. The power reserve portion determines an amount of power to be reserved and sends a signal, indicative of the determined amount of power to the power point tracking controller. The power point tracking controller determines a power point that is less than a MPP, and provides a signal to the power control portion indicative of the determined power point. The inertia control portion determines a virtual inertia and provides a signal indicative of the virtual inertia to the power control portion. The power control portion provides a power control signal to the inverter based on the power point tracking signal and the inertia command signal.

First claim

What is claimed is:

1. A method for operating a power system comprising the steps of:
receiving a DC power signal by an inverter;
controlling a power output of the inverter with an inverter controller, the inverter controller comprising a power control portion, a power reserve portion, a power point tracking control portion, and a virtual inertia control portion;
determining, with the power reserve portion, an amount of power to be reserved by the power point tracking control portion;
providing a power reserve signal, indicative of the determined amount of power to be reserved, from the power reserve portion to the power point tracking controller;
determining a power point by the power point tracking control portion that is less than a maximum power point;
providing a power point tracking signal to the power control portion that is indicative of the determined power point;
determining a virtual inertia with the virtual inertia control portion;
providing an inertia command signal indicative of the determined virtual inertia to the power control portion;
providing a power control signal from the power control portion to the inverter, wherein the control signal is based at least in part on the power point tracking signal and the inertia command signal; and
operating the inverter based at least in part on the power control signal.

2. The method of claim 1 , further comprising electrically coupling the inverter to a power source.

3. The method of claim 2 , wherein the power source comprises a photovoltaic (PV) generator.

4. The method of claim 1 , further comprising coupling the power system to an electrical load.

5. The method of claim 1 , wherein the determining a virtual inertia with the inertia control portion comprises one of determining a variable amount of virtual inertia, and determining a fixed amount of virtual inertia.

6. The method of claim 4 , wherein the virtual inertia is determined relative to a full load output of the power system.

7. The method of claim 4 , wherein the determining a virtual inertia with the inertia control portion is based at least in part on a signal input to the inertia control portion, wherein the signal input comprises at least one of a first reference signal received from a DC bus; a second reference signal received from the load, and a third reference signal received from the inverter.

8. The method of claim 4 , wherein the determining a virtual inertia with the inertia control portion is based at least in part on upon a control signal provided to the virtual inertia control portion by an external controller.

9. The method of claim 1 , wherein the determining a power point by the power point tracking control portion is based at least in part on a predetermined value stored in a look-up table.

10. The method of claim 9 , wherein the predetermined value is a percentage of the maximum power output of the power system.

11. The method of claim 1 , further comprising:
receiving, by the power control portion, a command signal from an external supervisory controller;
wherein the providing a power control signal from the power control portion to the inverter is further based at least in part on the command signal.

12. A virtual synchronous generator system for supplying power to an electrical load, comprising:
a DC-DC converter configured to receive power from a DC power source;
an inverter coupled to the DC-DC converter, arranged to receive a DC signal therefrom and configured to convert the DC signal to and AC signal;
an inverter controller coupled in signal communication to the inverter and configured to control an output of the inverter, the inverter controller comprising: a power point tracking control portion, a power reserve portion, a virtual inertia control portion, and a power control portion, wherein the power point tracking control portion is coupled in signal communication with the power reserve portion and the power control portion; and
wherein
the power reserve portion is configured to determine an amount of power to be reserved and to provide a power reserve signal, indicative of the determined amount of power to be reserved, to the power point tracking control portion;
the power point tracking control portion is configured to determine a power point that is less than a maximum power point for an output of the DC power source, and to provide a power point tracking signal to the power control portion indicative of the determined power point;
the virtual inertia control portion is coupled in signal communication to the power control portion, and configured to determine a virtual inertia, and to provide an inertia command signal indicative of the determined virtual inertia to the power control portion;
the power control portion is configured to provide a power control signal to the inverter, wherein the power control signal is based at least in part on the power point tracking signal and the virtual inertia command signal.

13. The virtual synchronous generator system of claim 12 , wherein an output of the inverter is configured to be electrically coupled to an electrical load.

14. The virtual synchronous generator system of claim 12 , wherein the virtual inertia is one of a variable amount of virtual inertia and a fixed amount of virtual inertia.

15. The virtual synchronous generator system of claim 13 , wherein the virtual inertia is determined relative to a full load output of the power system.

16. The virtual synchronous generator system of claim 13 , wherein the inertia control portion is configured to receive a signal input that comprises at least one of a first reference signal received from a DC bus, and a second reference signal received from the load, and a third reference signal received from the inverter.

17. The virtual synchronous generator system of claim 13 , wherein the signal input to the inertia control portion further comprises a control signal from an external controller.

18. The virtual synchronous generator system of claim 12 , wherein the power point tracking control portion is configured to determine the power point based at least in part on a predetermined value stored in a look-up table.

19. The virtual synchronous generator system of claim 18 , wherein the predetermined value is a percentage of the maximum power output of the power system.

20. The virtual synchronous generator system of claim 12 , wherein the power control portion is configured to receive a command signal from an external supervisory controller, and wherein the power control signal based at least in part on the command signal.

Assignees

• Gen Electric

Inventors

• Gong Maozhong

Classifications

• H02J2101/24

  Photovoltaics · CPC title

• H02J3/0014 Primary

  for preventing or reducing power oscillations in networks · CPC title

• H02J3/381

  Dispersed generators · CPC title

• H02M7/53871 Primary

  with automatic control of output voltage or current · CPC title

• Y02E10/56

  Power conversion systems, e.g. maximum power point trackers · CPC title