Control of reactive power in a wind power plant

Patent metadata

Field	Value
Publication number	US-10923918-B2
Application number	US-201415039514-A
Country	US
Kind code	B2
Filing date	Nov 4, 2014
Priority date	Nov 28, 2013
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

The invention relates to a method for controlling injection and absorption of reactive power in a wind power plant (WPP). In addition to wind turbine generators (WTG), the wind power plant comprises reactive power regulating devices, such as MSU and STATCOM devices. The reactive power regulating devices are controlled by wind power plant controller so that the combined amount of reactive power produced by the wind turbine generators and the reactive power regulating devices satisfies a desired amount of reactive power. In case of communication fault between the power plant controller and one of the reactive power regulating devices, the power plant controller is reconfigured so as to compensate the capability of the reactive power regulating device to inject or absorb the amount of reactive power.

First claim

What is claimed is:

1. A power plant controller for generating a setpoint to a wind turbine generator connected to an electrical grid, wherein the setpoint relates to a desired amount of reactive power to be produced by the wind turbine generator, wherein the power plant controller comprises:
a device controller configured to control operation of a reactive power regulating device on a power line between the wind turbine generator and the electrical grid, wherein the reactive power regulating device is configured to inject or absorb an amount of reactive power to or from the electrical grid via the power line,
a reference control system configured to determine the setpoint on basis of an electrical reference input and a measured electrical value, and
a communication fault detector configured to detect a communication fault between the power plant controller and the reactive power regulating device on the power line, wherein the communication fault indicates communication between the device controller and the reactive power regulating device has failed and the reactive power regulating device is no longer controllable by the power plant controller, wherein
the power plant controller is arranged to be reconfigured in response to (i) a detection of the communication fault and (ii) a detection of a difference between the electrical reference input and a second measured electrical value measured at a time after the detection of the communication fault, wherein the reconfigured power plant controller compensates for a capability of the reactive power regulating device to inject or absorb the amount of reactive power to or from the electrical grid.

2. A power plant controller according to claim 1 , wherein the power plant controller is arranged to perform the reconfiguration by stopping the device controller to control operation of the reactive power regulating device in response to the detection of the communication fault.

3. A power plant controller according to claim 1 , wherein the power plant controller comprises a limit function for limiting the setpoint to a maximum value, and wherein the power plant controller is arranged to perform the reconfiguration by reducing the maximum value by a value determined from a capacity value of the reactive power regulating device.

4. A power plant controller according to claim 1 , wherein the power plant controller is configured to perform the reconfiguration by distributing the setpoint among other reactive power regulating devices not affected by the communication fault and wind turbine generators.

5. A power plant controller according to claim 1 , wherein the power plant controller is configured to modify the setpoint by a feed-forward modification value, and wherein the power plant controller is further arranged to perform the reconfiguration by changing the feed-forward modification value by an amount corresponding to a capacity value of the reactive power regulating device or by reducing the feed-forward modification value to zero, in response to the detection of the communication fault.

6. A power plant controller according to claim 1 , wherein the power plant controller is arranged to perform the reconfiguration after a time delay after detection of the communication fault.

7. A power plant controller according to claim 1 , wherein, in response to a detection of no communication fault, the power plant controller is arranged to perform a configuration back into an original state, wherein the capability of the reactive power regulating device to inject or absorb the amount of reactive power to or from the electrical grid is no longer compensated.

8. A power plant controller according to claim 7 , wherein the power plant controller is arranged to perform the configuration back into the original state after a time delay, in response to a detection of no communication fault.

9. A wind power plant connectable to an electrical grid, wherein the wind power plant comprises at least one wind turbine generator, and the power plant controller according to claim 1 .

10. A method for generating a setpoint to a wind turbine generator connected to an electrical grid, wherein the method comprises:
controlling operation of a reactive power regulating device on a power line between the wind turbine generator and the electrical grid, wherein the reactive power regulating device is configured to inject or absorb an amount of reactive power to or from the electrical grid via the power line,
determining the setpoint on basis of an electrical reference input and a measured electrical value,
detecting a communication fault between a power plant controller and the reactive power regulating device on the power line, wherein the communication fault indicates communication between the power plant controller and the reactive power regulating device has failed and the reactive power regulating device is no longer controllable by the power plant controller,
after the detection of the communication fault, detecting a difference between the electrical reference input and a second measure electrical value, and
in response to detecting the communication fault and the difference between the electrical reference input and a second measure electrical value, reconfiguring the power plant controller so as to compensate for a capability of the reactive power regulating device to inject or absorb the amount of reactive power to or from the electrical grid.

11. At least one computer program product directly loadable into an internal memory of at least one digital computer, comprising software code portions for performing an operation for generating a setpoint to a wind turbine generator connected to an electrical grid when said at least one product is run on said at least one digital computer, the operation comprising:
controlling operation of a reactive power regulating device, wherein the reactive power regulating device on a power line between the wind turbine generator and the electrical grid is configured to inject or absorb an amount of reactive power to or from the electrical grid via the power line,
determining the setpoint on basis of an electrical reference input and a measured electrical value, wherein the setpoint relates to a desired amount of reactive power to be produced by the wind turbine generator
detecting a communication fault between a power plant controller and the reactive power regulating device on the power line, wherein the communication fault indicates communication between the power plant controller and the reactive power regulating device has failed and the reactive power regulating device is no longer controllable by the power plant controller,
after the detection of the communication fault, detecting a difference between the electrical reference input and a second measure electrical value, and
in response to detecting the communication fault and the difference between the electrical reference input and a second measure electrical value, reconfiguring the power plant controller so as to compensate for a capability of the reactive power regulating device to inject or absorb the amount of reactive power to or from the electrical grid.

Assignees

• Vestas Wind Sys As

Inventors

• Garcia Jorge Martinez
• Lærke Rasmus
• Møller Henrik B
• Nayebi Kouroush
• Rokofyllos Athanasios
• Wei Mu

Classifications

• H02J2101/28

  Wind energy · CPC title

• H02J2105/16

  being internal to power sources or power generation plants · CPC title

• Y02E40/30

  Reactive power compensation · CPC title

• Y02E10/76

  Power conversion electric or electronic aspects · CPC title

• H02J3/50

  Controlling the sharing of reactive power · CPC title