Decoupling synchrophasor based control system for multiple distributed energy resources

• US 10,027,119 B2
• Filed: 05/28/2016
• Issued: 07/17/2018
• Est. Priority Date: 05/28/2016
• Status: Active Grant

• Current Assignee: PXiSE Energy Solutions, LLC (Yokogawa Electric Corporation)
• Original Assignee: PXiSE Energy Solutions, LLC (Yokogawa Electric Corporation)
• Inventors: Wells, Charles H., de Callafon, Raymond A., Lee, Patrick T.
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US15/168,034
• Publication Number:
  US 20170346286A1
• Time in Patent Office: 780 Days
• Field of Search: 307 24
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/241 The oscillation concerning frequency
• CPC Class Codes: H02J 3/242 using phasor measuring units [PMU]
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks
• CPC Class Codes: Y04S 10/00 Systems supporting electrical power generation, transmission or distribution
• CPC Class Codes: Y04S 10/22 Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units

Abstract

A method and system to control distributed energy resources in an electric power system includes generation, storage and controllable loads. The system uses time synchronized measurements of voltage phasor and current phasors and their derivative information that may include real and reactive power to regulate and decouple both static and dynamic effects of real and reactive power flow through the local electric power system connected to the area electric power system. The method and system provides precise real and reactive power demand set point pairs; damping of real and reactive power fluctuations in the local electric power system; decoupling between real and reactive power demand response set points by means of a multivariable control system that uses time synchronized measurements of voltage and current phasors and their derivative information.

Claims

1. A method for decoupling control of real and reactive power of a local electrical power system having multiple distributed energy resources at non-co-located points, the method comprising:

feeding back time-synchronized measurements of voltage phasors and current phasors from multiple phasor measurement units to multivariable linear decoupling controllers; and

controlling the distributed energy resources by the multivariable linear decoupling controllers using linear control by sending, to the distributed energy resources, real and reactive power setpoint pairs derived from the time-synchronized measurements of voltage phasors and current phasors.

2. The method of claim 1, wherein the feeding back comprises feeding back phasor measurements from multiple level 1 controllers to a level 2 controller, and wherein the multivariable linear decoupling controllers form a hierarchical feedback control system.

3. The method of claim 1, wherein the feeding back comprises converting measured real and reactive power values to current and power angle phasors.

4. The method of claim 1, wherein the feeding back comprises converting measured real and reactive power values to voltages and voltage angle differences between points of interest and the distributed energy resources.

5. The method of claim 1, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a proportional-integral controller combined with a derivative filter to mitigate power grid disturbances, and an output filter to adjust output setpoint pairs according to a response characteristic of the distributed energy resources.

6. The method of claim 1, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using an internal predictive model to account for system dynamics and transport delay in obtaining phasor feedback.

7. The method of claim 1, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a feed forward filter for providing a faster phasor control in response to immediate set point changes.

8. The method of claim 1, wherein controlling the distributed energy resources comprises computing the real and reactive power setpoint pairs to achieve a predetermined power control at a Point Of Interest.

9. The method of claim 1, wherein the multiple distributed energy resources comprise a combination of energy generation devices, controllable energy loads, and energy storage devices.

10. A system for decoupling control of real and reactive power of a local electrical power system having multiple distributed energy resources at non-co-located points, the system comprising:

one or more controllers;

memory storing instructions which when executed by at least one controller result in operations comprising;

feeding back time-synchronized measurements of voltage phasors and current phasors from multiple phasor measurement units to multivariable linear decoupling controllers; and

controlling the distributed energy resources by the multivariable linear decoupling controllers using linear control algorithms by sending, to the distributed energy resources, real and reactive power setpoint pairs derived from the time-synchronized measurements of voltage phasors and current phasors.

11. The system of claim 10, wherein the feeding back comprises feeding back phasor measurements from multiple level 1 controllers to a level 2 controller, and wherein the multivariable linear decoupling controllers form a hierarchical feedback control system.

12. The system of claim 10, wherein the feeding back comprises converting measured real and reactive power values to current and power angle phasors.

13. The system of claim 10, wherein the feeding back comprises converting measured real and reactive power values to voltages and voltage angle differences between points of interest and the distributed energy resources.

14. The system of claim 10, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a proportional-integral controller combined with a derivative filter to mitigate power grid disturbances, and an output filter to adjust output setpoint pairs according to a response characteristic of the distributed energy resources.

15. The system of claim 10, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using an internal predictive model to account for system dynamics and transport delay in obtaining phasor feedback.

16. The system of claim 10, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a feed forward filter for providing a faster phasor control in response to immediate set point changes.

17. The system of claim 10, wherein controlling the distributed energy resources comprises computing the real and reactive power setpoint pairs to achieve a predetermined power control at a Point Of Interest.

18. The system of claim 10, wherein the multiple distributed energy resources comprise a combination of energy generation devices, controllable energy loads, and energy storage devices.

19. A controller having computer-readable program instructions, which when executed result in operations comprising:

feeding back time-synchronized measurements of voltage phasors and current phasors from multiple phasor measurement units to multivariable linear decoupling controllers; and

controlling the distributed energy resources by the multivariable linear decoupling controllers using linear control algorithms by sending, to the distributed energy resources, real and reactive power setpoint pairs derived from the time-synchronized measurements of voltage phasors and current phasors.

20. The controller of claim 19, wherein the feeding back comprises feeding back phasor measurements from multiple level 1 controllers to a level 2 controller, and wherein the multivariable linear decoupling controllers from a hierarchical feedback control system.

21. The controller of claim 19, wherein the feeding back comprises converting measured real and reactive power values to current and power angle phasors.

22. The controller of claim 19, wherein the feeding back comprises converting measured real and reactive power values to voltages and voltage angle differences between points of interest and the distributed energy resources.

23. The controller of claim 19, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a proportional-integral controller combined with a derivative filter to mitigate power grid disturbances, and an output filter to adjust output setpoint pairs according to a response characteristic of the distributed energy resources.

24. The controller of claim 19, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using an internal predictive model to account for system dynamics and transport delay in obtaining phasor feedback.

25. The controller of claim 19, wherein controlling the distributed energy resources by the multivariable linear decoupling controllers comprises using a feed forward filter for providing a faster phasor control in response to immediate set point changes.

26. The controller of claim 19, wherein controlling the distributed energy resources comprises computing the real and reactive power setpoint pairs to achieve a predetermined power control at a Point Of Interest.

27. The controller of claim 19, wherein the multiple distributed energy resources comprise a combination of energy generation devices, controllable energy loads, and energy storage devices.