Selective droop response control for a wind turbine power plant

Patent metadata

Field	Value
Publication number	US-9690267-B2
Application number	US-201214125354-A
Country	US
Kind code	B2
Filing date	Jun 12, 2012
Priority date	Jun 14, 2011
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A power plant controller ( 36 ) is described. The power plant controller ( 36 ) controls a power generation system ( 10 ) having one or more power generators ( 12 ) and an energy storage system ( 22 ), and provides a utility grid or transmission system operator with the capability to select the droop response provided by the power generation system. Accordingly, an operator can request a specific generator droop response in order to provide appropriate frequency and grid control services. The power plant controller ( 36 ) operates in real time determining one or more power characteristics of the power generation system ( 10 ). Based on these characteristics and an indication of a future predicted power output for the power generation system, the power plant controller can take the necessary steps to ensure that the power generation system is capable of responding with the selected droop response, or can advise the operator that a different droop is preferred.

First claim

The invention claimed is:

1. A power generation system comprising:
a power generator for generating power from a renewable energy resource;
a connection point connecting the power generator to a power grid, the connection point having a transformer with a low voltage side and a high voltage side, the power generator being coupled to the low voltage side;
an energy storage system coupled to the low voltage side of the connection point, wherein the energy storage system is operable to provide power to the power grid in addition to that provided by the power generator, or to store power generated by the power generator, so as to regulate the power output from the power generator to the grid;
a power plant controller that receives:
a power input indicating power characteristics of at least one of the grid, the power generator, the energy storage system, and the connection point, and
a request input from the power grid operator to provide power generation with a specified selectable droop response, wherein based on the power input and the specified selectable droop response, the power plant controller is configured to control the power generator and the energy storage system; and

wherein the power plant controller is configured to derate the power generator in advance of a time period when the specified selectable droop response has been requested in order to provide generation capacity to meet the specified selectable droop response.

2. The power generation system of claim 1 , wherein the power plant controller comprises a memory for logging requests from the power grid operator for a specified selectable droop response for future time periods.

3. The power generation system of claim 2 , wherein the power plant controller is operable to alert the power grid operator if a request from the power grid operator to provide power generation at specified selectable droop response coincides in time with a separate earlier request.

4. The power generation system of claim 1 , wherein the power plant controller determines a predicted future power output for a time period corresponding to a time period where a specified selectable droop response has been requested, and based on the determined predicted future power output controls one or more of the energy storage device and the power generator.

5. The power generation system of claim 4 , wherein based on the determined predicted future power output the power plant controller controls the energy storage device to ensure that it has a full charge to meet the request for the specified selectable droop response.

6. The power generation system of claim 1 , wherein the power plant controller issues an alarm when a selected droop response cannot be provided due to a shortfall in a predicted future power output, and/or the storage capacity of the energy storage system.

7. The power generation system of claim 1 , wherein the energy storage system is operable to:
store power from the power generator when the power produced by the generator is in excess of the power required by the power grid, and
output power to the grid when the power produced by the generator is less than the power required by the power grid.

8. The power generation system of claim 1 , wherein the selectable droop response includes one or more of, a droop setting, a droop response magnitude, and a droop response time.

9. The power generation system of claim 1 , wherein the power generator comprises one or more of a wind energy turbine, a wave or tidal energy turbine, or a solar cell.

10. The power generation system of claim 1 , wherein the power generator comprises a plurality of wind turbines in a wind park.

11. A power plant controller for controlling the operation of a power generation system comprising a power generator for generating power from a renewable energy resource, a connection point connecting the power generator to a power grid, the connection point having a transformer with a low voltage side and a high voltage side, the power generator being coupled to the low voltage side and an energy storage system coupled to the low voltage side of the connection point, wherein the energy storage system is operable to provide power to the power grid in addition to that provided by the power generator, or to store power generated by the power generator, so as to regulate the power output from the power generator to the grid, wherein the power plant controller is operable to:
receive a power input indicating power characteristics of at least one of the grid, the power generator, the energy storage system, and the connection point, and
a request input from the power grid operator to provide power generation at specified selectable droop response, wherein based on the power input and the specified selectable droop response, the power plant controller is configured to control the power generator and the energy storage system; and
wherein the power plant controller is configured to derate the power generator in advance of a time period when the specified selectable droop response has been requested in order to provide generation capacity to meet the specified selectable droop response.

12. A method of generation power using a power generation system comprising a power generator for generating power from a renewable energy resource, a connection point connecting the power generator to a power grid, the connection point having a transformer with a low voltage side and a high voltage side, the power generator being coupled to the low voltage side, and an energy storage system coupled to the low voltage side of the connection point, wherein the energy storage system is operable to provide power to the power grid in addition to that provided by the power generator, or to store power generated by the power generator, so as to regulate the power output from the power generator to the grid, the method comprising:
receiving, at a power plant controller, a power input indicating power characteristics of at least one of the grid, the power generator, the energy storage system, and the connection point;
receiving, at a power plant controller, a request input from a power grid operator to provide power generation at specified selectable droop response;
controlling the power generator and/or the energy storage system based on the power input and the specified selectable droop response; and
de-rating the power generator in advance of a time period when the specified selectable droop response has been requested in order to provide generation capacity to meet the specified selectable droop response.

13. The method of claim 12 , further comprising storing in memory requests from the power grid operator for a specified selectable droop response for future time periods.

14. The method of claim 13 , further comprising issuing an alert to the power grid operator if a request from the power grid operator to provide power generation at specified selectable droop response coincides in time with a separate earlier request.

15. The method of claim 12 , further comprising:
determining a predicted future power output for a time period corresponding to a time period where a specified selectable droop response has been requested; and
controlling one or more of the energy storage device and the power generator, based on the determined predicted future power output.

16. The method of claim 15 , further comprising controlling the energy storage device to ensure that it has a full charge to meet the request for the specified selectable droop response, based on the determined predicted future power output.

17.

Assignees

• Vestas Wind Sys As

Inventors

• Haj-Maharsi Mohamed
• Hoffman Jason

Classifications

• H02J2101/28

  Wind energy · CPC title

• H02S10/12

  Hybrid wind-PV energy systems · CPC title

• F03D9/255

  connected to electrical distribution networks; Arrangements therefor · CPC title

• F03D7/042

  by means of an electrical or electronic controller · CPC title

• F03D9/11

  storing electrical energy · CPC title