Wind farm and method for operating a wind farm

• US 10,461,536 B2
• Filed: 12/23/2011
• Issued: 10/29/2019
• Est. Priority Date: 12/29/2010
• Status: Active Grant

• Current Assignee: Siemens Gamesa Renewable Energy Service GmbH (Siemens AG)
• Original Assignee: Senvion SE
• Inventors: Fortmann, Jens
• Primary Examiner(s): Shechtman, Sean
• Application Number:
  US13/824,262
• Publication Number:
  US 20130175870A1
• Time in Patent Office: 2,867 Days
• Field of Search: None
• CPC Class Codes: F03D 9/257 the wind motor being part of a wind farm
• CPC Class Codes: F05B 2270/337 Electrical grid status parameters, e.g. voltage, frequency or power demand
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• 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: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

Operating a wind farm in which the power generated by the wind energy installations is fed to a power supply system via a system internal to the wind farm and via a substation is disclosed. The farm director of the wind farm can ascertain a standard target voltage value and transmit it to the control units of the individual wind energy installations on the wind farm, which can use an overall factor to regulate the reactive power generated by a wind energy installation. The overall factor can be calculated from the difference between the actual voltage across the wind energy installation and the target voltage value, multiplied by a gain factor. On account of the impedance in the internal system of the wind farm, wind energy installations situated far away from the substation thus generate less reactive power than the wind energy installations which are situated close to the substation.

Claims

1. A method for operating a wind farm having a plurality of wind energy installations, each wind energy installation having a control unit that is connected to an internal wind farm network, a substation at which electrical power that is generated on the wind farm is delivered by the internal wind farm network to a power supply network, and a farm master that is connected to the control unit of each wind energy installation of the plurality of wind energy installations, the method comprising:

determining, by the farm master, a uniform target voltage value,

transmitting, by the farm master, the uniform target voltage value to the control unit of each wind energy installation of the plurality of wind energy installations,

determining, by a control unit of a wind energy installation of the plurality of wind energy installations, an overall factor for setting the reactive power generated by the wind energy installation, and

setting, by the control unit of the wind energy installation of the plurality of wind energy installations, the reactive power generated by the wind energy installation according to the overall factor to reduce reactive power losses in the internal wind farm network, wherein the overall factor comprises a first factor that is calculated from a difference between an actual voltage present at the wind energy installation and the uniform target voltage value, multiplied by a gain factor, wherein the gain factor comprises a summation of a global gain factor and an individual gain factor for each wind energy installation.

2. The method of claim 1, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from a difference between the actual voltage present at the wind energy installation averaged over a specified period of time and the target voltage value, multiplied by the gain factor.

3. The method of claim 1, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from the difference averaged over a specified period of time between the actual voltage present at the wind energy installation and the target voltage value, multiplied by the gain factor.

4. The method of claim 1, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from the difference between the actual voltage present at the wind energy installation and the target voltage value averaged over a specified period of time, multiplied by the gain factor.

5. The method of claim 1, wherein one or both of the global gain factor and the individual gain factors is determined by the farm master and is transmitted to the control units of the plurality of wind energy installations.

6. The method of claim 1, wherein an individual target voltage correction factor is provided for each of the plurality of wind energy installations and the difference between the actual voltage present at the wind energy installation and the target voltage value is reduced by the individual target voltage correction factor provided for the wind energy installation.

7. The method of claim 6, wherein the individual target voltage correction factors are determined by the farm master and transmitted to the control unit of each wind energy installation of the plurality of wind energy installations.

8. The method of claim 6, wherein the gain factor comprises a global gain factor and an individual gain factor provided for each of the plurality of wind energy installations, wherein at least two wind energy installations of the plurality of wind energy installations are combined into a group, and wherein one or both of the individual gain factor and the individual target voltage correction factor are shared by the group.

9. A wind farm comprising:

a plurality of wind energy installations, each wind energy installation having a control unit, which are connected to an internal wind farm network,

a substation at which electrical power that is generated on the wind farm is delivered by the internal wind farm network to a power supply network, and

a farm master that is connected to the control unit of each wind energy installation of the plurality of wind energy installations,

wherein the farm master is configured to determine a uniform target voltage value and to transmit the uniform target voltage value to the control unit of each wind energy installation of the plurality of wind energy installations, and the control unit of each wind energy installation is configured to;

determine an overall factor for setting reactive power of the respective wind energy installation, wherein the overall factor comprises a first factor that is calculated from a difference between an actual voltage present at the respective wind energy installation and the target voltage value, multiplied by a gain factor, wherein the gain factor comprises a summation of a global gain factor and an individual gain factor for each wind energy installation, and

control reactive power generated by the respective wind energy installation by setting the reactive power generated by the respective wind energy installation according to the overall factor to reduce reactive power losses in the internal wind farm network.

10. The wind farm of claim 9, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from a difference between the actual voltage present at the wind energy installation averaged over a specified period of time and the target voltage value, multiplied by the gain factor.

11. The wind farm of claim 9, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from the difference averaged over a specified period of time between the actual voltage present at the wind energy installation and the target voltage value, multiplied by the gain factor.

12. The wind farm of claim 9, wherein the overall factor comprises another factor to be added to the first factor, wherein the another factor is calculated from the difference between the actual voltage present at the wind energy installation and the target voltage value averaged over a specified period of time, multiplied by the gain factor.

13. The wind farm of claim 9, wherein one or both of the global gain factor and the individual gain factors are determined by the farm master and transmitted to the control unit of each wind energy installation of the plurality of wind energy installations.

14. The wind farm of claim 9, wherein an individual target voltage correction factor is provided for each of the plurality of wind energy installations and the difference between the actual voltage present at the wind energy installation and the target voltage value is reduced via an individual target voltage correction factor provided for the wind energy installation.

15. The wind farm of claim 14, wherein the individual target voltage correction factors are determined by the farm master and transmitted to the control unit of each wind energy installation of the plurality of wind energy installations.

16. The wind farm of claim 14, wherein the gain factor comprises a global gain factor and an individual gain factor provided for each of the plurality of wind energy installations, wherein at least two wind energy installations of the plurality of wind energy installations are combined into a group, and wherein one or both of the individual gain factor and the individual target voltage correction factor are shared by the group.