METHOD FOR PROVIDING REACTIVE POWER

Abstract

Provided is a method for controlling an electrical installation, in particular a wind power installation or a wind farm. The method includes determining a specific location within an electrical supply network to which the electrical installation is electrically connected via the electrical supply network, determining an electrical variable which maps an electrical distance between the electrical installation and the specific location and ascertaining a potential reactive power of the electrical installation for the specific location depending on the electrical variable which maps an electrical distance between the electrical installation and the specific location.

Claims

1. A method for controlling an electrical installation, comprising: determining a specific location within an electrical supply network to which the electrical installation is electrically connected via the electrical supply network; determining an electrical variable which represents a distance in the electrical supply network between the electrical installation and the specific location; and determining a potential reactive power of the electrical installation for the specific location depending on the electrical variable.

2. The method for controlling the electrical installation as claimed in claim 1, wherein the electrical installation is a wind power installation or a wind farm.

3. The method for controlling the electrical installation as claimed in claim 1, wherein the electrical variable is an impedance between the electrical installation and the specific location.

4. The method for controlling the electrical installation as claimed in claim 3, wherein the impedance is an effective impedance.

5. The method for controlling the electrical installation as claimed in claim 3, wherein the impedance is an equivalent impedance between the electrical installation and the specific location.

6. The method for controlling the electrical installation as claimed in claim 1, comprising: transmitting the determined potential reactive power to a network operator.

7. The method for controlling the electrical installation as claimed in claim 1, comprising: generating and feeding the determined potential reactive power into the electrical supply network.

8. The method for controlling the electrical installation as claimed in claim 1, comprising: determining the potential reactive power depending on an operating point of the electrical installation.

9. The method for controlling the electrical installation as claimed in claim 8, comprising: determining the operating point of the electrical installation depending on a requested reactive power.

10. The method for controlling the electrical installation as claimed in claim 9, wherein the requested reactive power is requested by a network operator.

11. The method for controlling the electrical installation as claimed in claim 1, wherein the specific location is specified by a network operator of the electrical supply network.

12. The method for controlling the electrical installation as claimed in claim 1, comprising: determining the potential reactive power using iterative requests and responses by a network operator and the electrical installation.

13. The method for controlling the electrical installation as claimed in claim 1, wherein the method is performed by a wind power installation or a wind farm.

14. A wind power installation, comprising: a controller configured to perform the method as claimed in claim 1, wherein the controller includes an interface configured to receive data from a network operator and/or send data to the network operator.

15. A wind farm, comprising: a wind farm controller configured to perform the method as claimed in claim 1, wherein the wind farm controller includes an interface configured to receive data from a network operator and/or send data to the network operator.

16. A method for controlling an electrical supply network, comprising: determining a specific location within the electrical supply network; specifying a reactive power set point for the specific location; receiving a potential reactive power for the specific location from at least one electrical installation; and requesting a reactive power from the at least one electrical installation for the specific location depending on the reactive power set point and the received potential reactive power.

17. The method for controlling the electrical supply network as claimed in claim 16, comprising: requesting the potential reactive power for the specific location from the at least one electrical installation.

18. The method for controlling the electrical supply network as claimed in claim 16, wherein the reactive power set point is determined such that a voltage boost occurs at the specific location within the electrical supply network.

19. The method for controlling the electrical supply network as claimed in claim 16, wherein the specific location has a line voltage that is below a nominal line voltage.

20. The method for controlling the electrical supply network as claimed in claim 19, wherein the line voltage that is below 0.95 per unit (p.u.) of the nominal line voltage.

21. The method for controlling the electrical supply network as claimed in claim 16, wherein requesting the reactive power occurs iteratively.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0059] The present invention is explained in greater detail hereinafter by way of example using exemplary embodiments with reference to the accompanying figures, wherein the same reference symbols are used for the same or similar components.

[0060] FIG. 1 shows a schematic view of a wind power installation according to one embodiment.

[0061] FIG. 2A shows a structure of an electrical supply network with a wind power installation according to one embodiment.

[0062] FIG. 2B shows a further structure of an electrical supply network with a wind power installation according to one embodiment.

[0063] FIG. 3 shows a schematic sequence of a method for controlling a wind power installation in one embodiment.

DETAILED DESCRIPTION

[0064] FIG. 1 shows a schematic view of a wind power installation 100 according to one embodiment.

[0065] The wind power installation 100 has a tower 102 and a nacelle 104.

[0066] An aerodynamic rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104.

[0067] The rotor 106 is transferred into a rotational movement by the wind during operation and thus drives a generator in the nacelle 104.

[0068] The generator is further connected to a power converter described herein, by means of which the wind power installation exchanges electrical power with an electrical supply network.

[0069] In particular, the wind power installation is therefore designed as a converter-based feeder.

[0070] A control unit (e.g., controller) described herein is further provided for operating the wind power installation, and in particular the power converter, in particular in order to carry out and/or participate in a method described herein.

[0071] FIG. 2A shows a structure of an electrical supply network 2000 with a wind power installation 100 according to one embodiment.

[0072] The electrical supply network 2000 comprises a plurality of lines L1, L2, L3, L4, L5 as well as producers E1, E2, E3 and consumers V1, V2, V3 connected to these lines L1, L2, L3, L4, L5 and a wind power installation 100.

[0073] The wind power installation 100 is designed as described herein and is preferably representative of a wind farm 1000.

[0074] The electrical supply network 2000 is further operated by a network operator 3000 which is connected to the wind power installation 100 via a communication line K1, for example, in particular in order to exchange data.

[0075] In addition, the electrical supply network 2000 comprises a specific location P, preferably determined by the network operator 3000, at which in particular the actual voltage of the electrical supply network is to be raised by means of the wind power installation 100, for example because the specific location P has an undervoltage.

[0076] Between the specific location P, which is located on a nodal point of two electrical lines, for example, and the wind power installation 100, there is an electrical distance which can be reproduced (represented) by the impedance Z.

[0077] In this case, the, in particular effective, impedance Z is composed of the line impedance ZL4′ and the line impedance ZL5′. In particular, the partial parallel connection of the lines L4 and L5 ensures another, in particular effective, impedance Z between the specific location P and the wind power installation 100. In the present case, the effective impedance Z is thus smaller than the effective impedance Z shown in FIG. 2B.

[0078] There may also be a mesh network between the specific location and the electrical installation. In such a case, the effective impedance Z of the mesh network is then to be considered for the method described herein.

[0079] In order to raise the actual voltage of the electrical supply network 2000 at the specific location P by means of the wind power installation 100, the method described herein is carried out.

[0080] FIG. 2B shows a further structure of an electrical supply network 2000 with a wind power installation 100 according to one embodiment.

[0081] The electrical supply network 2000 comprises a plurality of lines L1, L2, L3, L4 as well as producers E1, E2, E3 and consumers V1, V2, V3 connected to these lines L1, L2, L3, L4 and a wind power installation 100.

[0082] The wind power installation 100 is designed as described herein and is preferably representative of a wind farm 1000.

[0083] The electrical supply network 2000 is further operated by a network operator 3000 which is connected to the wind power installation 100 via a communication line K1, for example, in particular in order to exchange data.

[0084] In addition, the electrical supply network 2000 comprises a specific location P, preferably determined by the network operator 3000, at which in particular the actual voltage of the electrical supply network is to be raised by means of the wind power installation 100, for example because the specific location P has an undervoltage.

[0085] Between the specific location P, which is located on a nodal point of two electrical lines, for example, and the wind power installation 100, there is an electrical distance which can be reproduced by the impedance Z.

[0086] In this case, the, in particular effective, impedance Z is composed of the line impedance ZL4′.

[0087] In order to raise the actual voltage of the electrical supply network 2000 at the specific location P by means of the wind power installation 100, the method described herein is carried out.

[0088] FIG. 3 shows a schematic sequence 300 of a method for controlling a wind power installation 100 in one embodiment.

[0089] In a first step 310, a specific location P within an electrical supply network 2000 is determined to which the wind power installation 100 is electrically connected via the electrical supply network, for example via an electrical line L4.

[0090] In one further step 320, an electrical variable, in particular an (effective) impedance Z, is determined which maps an electrical distance between the wind power installation and the specific location P.

[0091] In one further step 330, a potential reactive power of the wind power installation is then ascertained for the specific location P depending on the electrical variable, in particular the impedance Z.

[0092] This potential reactive power ascertained in this way can then be transmitted to a network operator of the electrical supply network, for example, which can retrieve the potential reactive power if required from the wind power installation or the operator of the wind power installation, for example in order to raise the actual voltage of the electrical supply network at the specific location P.

[0093] The communication between the wind power installation 100 and the network operator 3000 can take place in a wired or wireless manner, for example.

[0094] The wind power installation has a control unit described previously for communicating with the network operator 3000, for example.

[0095] Furthermore, the method described previously can also be carried out with a wind farm. In such a case, the wind farm has a wind farm control unit (e.g., wind farm controller), for example, with which the network operator can then communicate.

[0096] In this case, the method described previously is particularly well suitable for a, preferably technical, aggregation of electrical power, in particular electrical reactive power, preferably in wind power installations or wind farms.

[0097] The method described previously is therefore particularly well suitable for: [0098] an aggregation of a plurality of wind farms to form a renewable power plant; [0099] a network control of the electrical supply network during normal operation; [0100] a network control of the electrical supply network during critical network situations; [0101] a voltage control of a network operator of the electrical supply network; [0102] an optimized power flow controller of a network operator of the electrical supply network,
in particular in the case of methods in which reactive power is required, in particular for voltage setting.

LIST OF REFERENCE SYMBOLS

[0103] 100 wind power installation [0104] 102 tower, in particular of a wind power installation [0105] 104 nacelle, in particular of a wind power installation [0106] 106 aerodynamic rotor, in particular of a wind power installation [0107] 108 rotor blade, in particular of a wind power installation [0108] 110 spinner, in particular of a wind power installation [0109] 300 sequence of a method for controlling an electrical installation [0110] 310 determining a specific location [0111] 320 determining an electrical variable [0112] 330 ascertaining a potential reactive power [0113] 1000 wind farm [0114] 2000 electrical supply network [0115] 3000 network operator, in particular of the electrical supply network [0116] E1, E2, E3 producers, in particular of the electrical supply network [0117] K1 communication line, in particular of the network operator [0118] L1, L2 . . . electrical lines, in particular of the electrical supply network [0119] L3, L4, L5 electrical lines, in particular of the electrical supply network [0120] P specific location, within the electrical supply network [0121] V1, V2, V3 consumers, in particular of the electrical supply network [0122] Z impedance, in particular of an electrical distance [0123] z.sub.L4′, z.sub.L5′ line impedance

[0124] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.