DYNAMIC WIND-ENERGY PLANT

Abstract

A method for controlling an electricity distribution grid having a nominal grid voltage, in particular in a critical grid situation, wherein a grid control center is provided for controlling the electricity distribution grid and the electricity distribution grid has at least one control region that comprises a plurality of mutually geographically separate wind farms, comprising the steps of: querying power outputs available from the wind farms, in particular on the basis of a weather forecast; defining a control node within the control region, in particular on the basis of the queried available power out-puts, preferably performed by the grid operator; combining a number of wind farms at the calculated control node to form a wind power plant on the basis of the queried available power outputs and/or a probability distribution of the available power output; controlling the wind power plant, in particular through the grid control center, by way of a wind power plant control unit, such that a required voltage quality and/or frequency stability and/or uninterrupted availability is provided in the control region.

Claims

1. A method for controlling an electricity distribution grid having a nominal grid voltage, wherein a grid control center is coupled to the electricity distribution grid, wherein the electricity distribution grid has a control region that comprises a plurality of wind farms geographically separated from each other, the method comprising: querying power outputs available from the plurality of wind farms; defining a control node within the control region; combining the plurality of wind farms at the calculated control node to form a wind power plant based on the queried available power outputs or a probability distribution of the available power output or both; and controlling the wind power plant using a wind power plant controller such that a specified voltage quality, a frequency stability, or an uninterrupted availability, or a combination thereof is provided in the control region.

2. The method as claimed in claim 1, wherein the plurality of wind farms are combined based on a predefined minimum power output with a minimum availability, wherein the predefined minimum power output depends on a size of the control region.

3. The method as claimed in claim 1, wherein the control node is defined dynamically, and wherein the plurality of wind farms are combined dynamically at the calculated control node to form the wind power plant.

4. The method as claimed in claim 1, wherein a critical grid situation is a situation from the following list, comprising: voltage drop, voltage failure, transient process, system split, underfrequency, overfrequency, and definition by staff in the grid control center.

5. The method as claimed in claim 1, wherein the electricity distribution grid is controlled to generate a stable voltage in the control area that is between 90 and 110 percent of the nominal grid voltage.

6. The method as claimed in claim 1, wherein: the wind power plant has a rated power output of at least 250 megawatts (MW) or more, and/or the wind power plant has at least a forecast actual power output of at least 100 MW.

7. The method as claimed in claim 1, wherein a first wind farm of the plurality of wind farms is at most 100 kilometers (km) cable length away from a second wind farm of the plurality of wind farms.

8. The method as claimed in claim 1, wherein querying the power output available from the plurality of wind farms comprises querying power outputs available from the plurality of wind farms based on a weather forecast.

9. The method as claimed in claim 1, wherein the available power outputs are calculated based on at least one weather forecast.

10. The method as claimed in claim 1, wherein combining the plurality of wind farms are combined to form the wind power plant based on one from the following list, comprising: a control region status, a control region size, a current control region load, and a location of the control node.

11. The method as claimed claim 1, wherein a quantity of the plurality of wind farms is based on at least one from the following list, comprising: a control region status, a control region size, a current control region load, a location of the control node, and based on a wind power plant rated power output.

12. The method as claimed in claim 1, wherein setpoint values are predefined for controlling the wind power plant, comprising at least one from the following list: active power, reactive power, setpoint frequency, active power/frequency statics, setpoint voltage, and reactive power/voltage statics.

13. A wind farm comprising: a controller configured to: receive setpoint values query power outputs available from a plurality of wind farms; define a control node within the control region; combine the plurality of wind farms at the calculated control node to form a wind power plant based on the queried available power outputs or a probability distribution of the available power output or both; and control the wind power plant using a wind power plant controller such that a specified voltage quality, a frequency stability, or an uninterrupted availability, or a combination thereof is provided in the control region.

14. (canceled)

15. The method as claimed in claim 1, wherein the nominal grid voltage is a critical grid situation.

16. The method as claimed in claim 1, wherein combining the plurality of wind farms at the calculated control node to form the wind power plant comprises dynamically combining the plurality of wind farms.

17. The method as claimed in claim 1, wherein defining the control node within the control region comprises defining the control node within the control region based on the queried available power outputs.

18. The method as claimed in claim 17, wherein the queried available power outputs are obtained by the grid operator.

19. The method as claimed in claim 1, wherein controlling the wind power plant comprises controlling the wind power plant using the grid control center.

20. The method as claimed in claim 9, wherein the available power outputs are calculated using a risk factor of less than 1 and a probability distribution.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0055] The present invention will now be explained in more detail below by way of example and on the basis of exemplary embodiments with reference to the accompanying figures, wherein the same reference symbols are used for similar or functionally identical components.

[0056] FIG. 1 shows a schematic view of a wind power installation according to the invention of a wind farm according to the invention in one embodiment,

[0057] FIG. 2 shows a schematic structure of a wind farm according to the invention in one embodiment,

[0058] FIG. 3 shows a schematic sequence of a method according to the invention in one embodiment,

[0059] FIG. 4A schematically shows a control region of an electricity distribution grid,

[0060] FIG. 4B shows a structure of the wind power plant in an electricity distribution grid, in particular the querying of power outputs available from the wind farms,

[0061] FIG. 4C shows a structure of the wind power plant in an electricity distribution grid, in particular the definition of a control node, and FIG. 4D shows a structure of the wind power plant in an electricity distribution grid, in particular the combination of wind farms to form a wind power plant and subsequent control.

DETAILED DESCRIPTION

[0062] FIG. 1 shows a wind power installation 100 of a wind farm according to the invention.

[0063] The wind power installation 100 to this end has a tower 102 and a nacelle 104. An aerodynamic rotor 106 having three rotor blades 108 and having a spinner 110 is arranged on the nacelle 104. The rotor 106 is set in a rotational movement by the wind during operation and thereby drives a generator in the nacelle 104. As a result, the generator generates a current that is fed, by way of a full converter, to a wind power installation transformer that is connected to a wind farm grid.

[0064] FIG. 2 shows a schematic structure of a wind farm 1000 according to the invention in one embodiment.

[0065] The wind farm 1000 comprises a plurality of wind power installations 1100, as shown by way of example in FIG. 1, which are connected to one another via a common wind farm grid 1200.

[0066] The wind farm grid 1200 is connected to an electricity distribution grid 2000 by way of a wind farm transformer 1300 in order to feed in an electric wind farm power output P.sub.park, which consists of a sum of the individual electric wind power installation power outputs P.sub.wea.

[0067] The wind farm 1000 furthermore has a wind farm control unit 1400 for controlling the wind farm 1000.

[0068] The wind farm control unit 1400 comprises a wind power plant interface 1410, a grid operator interface 1420 and a wind power installation interface 1430.

[0069] The wind power plant interface 1410 is designed at least to receive setpoint values S.sub.WPP from a wind power plant control unit 3000.

[0070] The grid operator interface 1420 is designed at least to receive setpoint values S.sub.GO from a grid control center 4000, in particular of the grid operator, and to transmit an available power output P.sub.avail, in particular on the basis of a weather forecast, to the grid control center 4000.

[0071] The wind power installation interface 1430 is designed to transmit setpoint values S.sub.WF to the wind power installations 1100 of the wind farm 1000, for example active power setpoint values, in order to control the wind farm 1000 and in particular the electric wind farm power output P.sub.park.

[0072] To this end, the wind power installations 1100 each have at least one wind power installation control unit 1180, which receive the setpoint values S.sub.WF from the wind farm control unit 1400 and are designed to be operated at least with a set of operating parameters.

[0073] The wind farm control unit 1400 preferably also has a grid monitoring system 1440 that is designed to record at least one grid variable, such as for example the grid voltage U.sub.grid.

[0074] FIG. 3 shows a schematic sequence of a method 5000 according to the invention for controlling an electricity distribution grid, in particular as shown below in FIGS. 4A to 4D.

[0075] In a first step 5100, the grid control center queries the power outputs P.sub.avail available from the wind farms.

[0076] In a following step 5200, a control node SLACK is then defined within the control region, in particular by the grid operator, on the basis of the queried available power outputs P.sub.avail.

[0077] In a further step 5300, a number of wind farms are then combined at the calculated control node SLACK to form a wind power plant WPP.

[0078] It is thus proposed in particular for both the control node SLACK and the power output of the wind power plant WPP to be performed by the grid operator.

[0079] The wind power plant WPP is then controlled by way of a wind power plant control unit such that a required voltage quality and/or frequency stability and/or uninterrupted availability is provided in the control region.

[0080] The wind power plant control unit thus uses the combined wind farms to form a wind power plant, in particular by way of a wind power plant controller. For this purpose, test and feedback entities are preferably provided within the wind power plant controller, these indicating whether the wind power plant is actually able to be operated properly with the required information. The test and feedback entities are particularly preferably in an online-based form.

[0081] FIG. 4A schematically shows a control region 6000 of an electricity distribution grid, wherein the electricity distribution grid has a grid control center 6100 for controlling the electricity distribution grid.

[0082] The control region 6000 comprises a plurality of consumers Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, generators G.sub.1, G.sub.2 and wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4, which are connected to one another via power lines C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5.

[0083] The control region 6000 is thus part of the electricity distribution grid or may also be the entire electricity distribution grid. If the control region is only part of the electricity distribution grid, the control region contains for example further power lines C.sub.6, C.sub.7, C.sub.8 to other parts of the electricity distribution grid.

[0084] The generators G.sub.1, G.sub.2 are for example conventional power plants, such as for example coal-fired power plants.

[0085] The consumers Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4 are for example industrial buildings, residential dwellings and the like.

[0086] The wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4 are preferably wind farms, as shown for example in FIG. 2, wherein the wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4 are geographically separate from one another.

[0087] In order to control the load flow in the electricity distribution grid or to control the electricity distribution grid, the grid control center is connected to the generators, that is to say the generators G.sub.1, G.sub.2 and the wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4, by the signal lines L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 so as to convey signals, in particular in order to exchange setpoint values and available power outputs.

[0088] In order to carry out the method described above or below, the grid control center 6100 furthermore comprises a wind power plant control unit 6200, which is connected to the wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4 of the control region by way of the signal lines L.sub.1, L.sub.2, L.sub.3, L.sub.4.

[0089] FIG. 4B shows a structure of the wind power plant in an electricity distribution grid, as shown in particular in FIG. 4A, in particular the querying of power outputs available from the wind farms, in particular as shown in FIG. 3 with method step 5100.

[0090] The control region by way of example contains a fault F on the power line C.sub.4, which causes a critical grid situation in the electricity distribution grid.

[0091] In response thereto, the grid control center 6100 activates the wind power plant control unit 6200, which queries the power output P.sub.avail available from the wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4 in the control region 6000 via the signal lines L.sub.1, L.sub.2, L.sub.3, L.sub.4.

[0092] The wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4 then report their available power output to the wind power plant control unit 6200 via the signal lines L.sub.1, L.sub.2, L.sub.3, L.sub.4.

[0093] FIG. 4C shows a structure of the wind power plant in an electricity distribution grid, as shown in particular in FIG. 4A, in particular the definition of a control node SLACK, in particular as shown in FIG. 3 with method step 5200.

[0094] After the wind power plant control unit 6200 has received the power outputs P.sub.avail available from the wind farms WF.sub.1, WF.sub.2, WF.sub.3, WF.sub.4, the wind power plant control unit 6200 calculates a control node SLACK on the basis of the available power outputs.

[0095] FIG. 4D shows a structure of the wind power plant in an electricity distribution grid, as shown in particular in FIG. 4A, in particular the combination of wind farms WF.sub.1, WF.sub.2, WF.sub.4 to form a wind power plant WPP and subsequent control the wind power plant WPP through setpoint values S.sub.wpp, in particular as shown in FIG. 3 with method steps 5300 and 5400.

[0096] After the wind power plant control unit 6200 has calculated and defined the control node SLACK, the wind farms WF.sub.1, WF.sub.2, WF.sub.4 are dynamically combined to form a functional unit and controlled by the wind power plant control unit 6200.

[0097] The wind farms WF.sub.1, WF.sub.2, WF.sub.4, the wind power plant control unit 6200 and the control node thus form the wind power plant, in particular a virtual wind power plant, in relation to the control region.

[0098] The structure of this wind power plant WPP is dynamic in this case, that is to say, in the course of the method according to the invention, further wind farms WF.sub.4 may be added to the wind power plant or wind farms WF.sub.1, WF.sub.2, WF.sub.4 of the wind power plant may be removed from the wind power plant WPP.