Method for feeding electrical power into an electrical supply network

Patent metadata

Field	Value
Publication number	US-11898540-B2
Application number	US-202117565283-A
Country	US
Kind code	B2
Filing date	Dec 29, 2021
Priority date	Dec 30, 2020
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

Provided is a method for feeding electrical power into an electrical supply network using a converter-controlled infeed apparatus. The apparatus feeds into a local network section of the electrical supply network at a network connection point. The network has further infeed apparatuses and consumers for consuming electrical power. The local section has a ratio of power able to be fed in using converters to a total power able to be fed in by all infeed apparatuses of at least 50%. A controller controls the infeed of the electrical power depending on a network state of the network. The controller has control behavior that depends on a network characteristic of the local section. The network characteristic is dependent on at least one property of the local section and at least one property of a further network section of the network or a determination that no further network section is present.

First claim

The invention claimed is:

1. A method for feeding electrical power into an electrical supply network using a converter-controlled infeed apparatus that feeds the electrical power into the electrical supply network using at least one converter, comprising:
feeding, by the converter-controlled infeed apparatus, the electrical power into a local network section of the electrical supply network at a network connection point, wherein:
the electrical supply network includes:
a plurality of infeed apparatuses including the converter-controlled infeed apparatus and one or more other infeed apparatuses, for feeding infeed power including the electrical power of the converter-controlled infeed apparatus, and
a plurality of consumers for consuming a consumption power, and

the local network section has a converter pervasion of at least 50%, wherein the converter pervasion is a ratio of a rated power of converter-controlled infeed apparatuses of the plurality of infeed apparatuses to a total rated power of the plurality of infeed apparatuses; and

controlling, by a controller, the feeding of the electrical power of the converter-controlled infeed apparatus depending on a network state of the electrical supply network, wherein:
the controller has a control behavior that is selected or set depending on a network characteristic of the local network section, and the network characteristic is dependent on:
at least one property of the local network section and at least one property of another network section of the electrical supply network, the other network section being coupled to the local network section, or
the at least one property of the local network section and a determination that another network section is not coupled to the electrical supply network,

wherein the network characteristic of the local network section is an island network in response to:
the local network section corresponding to the electrical supply network,
the electrical supply network forming a self-contained network, and
a sum of consumption powers of the plurality of consumers coupled to the electrical supply network does not exceed 5 gigawatt (GW),

wherein the network characteristic of the local network section is a section with high converter pervasion coupled to a strong network in response to:
the local network section being coupled to a superordinate network section relative to the local network section,
the sum of the consumption powers of the plurality of consumers coupled to the electrical supply network exceeding 5 GW,
the superordinate network section being part of the electrical supply network, and
the superordinate network section has a high centrifugal mass index of at least 50%, and/or a power exchange capacity with respect to the local network section, wherein the centrifugal mass index is a ratio between electrical power able to be fed into the superordinate network section by directly coupled synchronous generators to a total power able to be fed into the superordinate network section,

wherein the network characteristic of the local network section is a section with locally high converter pervasion coupled to a normal network in response to:
converter-controlled infeed apparatuses of the local network section being coupled to the local network section with an average short circuit ratio having a value of a maximum of 4,
the local network section being coupled to the superordinate network section,
the sum of the consumption powers of the plurality of consumers coupled to the electrical supply network exceeding 5 GW,
the superordinate network section being part of the electrical supply network, and
the superordinate network section having a centrifugal mass index between 20% and 100%,

wherein the network characteristic of the local network section is a section with high converter pervasion coupled to a network with high converter pervasion in response to:
the local network section being coupled to the superordinate network section,
the sum of the consumption powers of the plurality of consumers coupled to the electrical supply network exceeding 5 GW,
the superordinate network section being part of the electrical supply network, and
the superordinate network section having a low centrifugal mass index and

wherein the network characteristic of the local network section is a section with indefinite behaviors in response to the network characteristic not being the island network, the section with the high converter pervasion coupled to the strong network, the section with the locally high converter pervasion coupled to the normal network or the section with the high converter pervasion coupled to the network with the high converter pervasion.

2. The method as claimed in claim 1 , wherein:
the converter-controlled infeed apparatus is a wind power installation, a wind farm comprising a plurality of wind power installations or a photovoltaic installation, and
the one or more other infeed apparatuses are a conventional generator, a gas turbine or a diesel generator.

3. The method as claimed in claim 1 , wherein:
the high centrifugal mass index is defined by a value that is above a predefinable centrifugal mass reference index,
the power exchange capacity is a ratio between maximum power exchangeable between the superordinate network section and the local network section in relation to power able to be fed in by the plurality of infeed apparatuses of the local network section and is at least 50%, and
the low centrifugal mass index is below the predefinable centrifugal mass reference index or below a second centrifugal mass reference value.

4. The method as claimed in claim 1 , comprising:
selecting or setting the control behavior depending on the network state of the electrical supply network; and/or
selecting or setting the control behavior depending on a converter infeed proportion of the local network section, wherein the converter infeed proportion is a ratio of power fed in by converters of the local network section to a total power fed in by the plurality of infeed apparatuses of the local network section.

5. The method as claimed in claim 1 , wherein the control behavior is selected or set depending on a vertical network load of the local network section or the superordinate network section of the local network section that has a higher voltage than the local network section, wherein the vertical network load is a sum of all power transmissions from a transmission network coupled to the network section via directly coupled transformers.

6. The method as claimed in claim 1 , wherein:
the control behavior is set depending on a voltage softness of the local network section or the superordinate network section of the local network section that has a higher voltage than the local network section, and
the voltage softness is a reciprocal of a quotient between:
a value of a relative reactive power change as change in total reactive power fed into the local network section, relative to a maximum reactive power configured to fed into the local network section, and
a value of a relative voltage change resulting from the change in the fed-in reactive power at a reference point of the local network section.

7. The method as claimed in claim 1 , wherein the control behavior is set depending on a frequency softness of the local network section or the superordinate network section of the local network section that has a higher voltage than the local network section, wherein the frequency softness is a reciprocal of a quotient between a value of a relative change in a total active power fed into the local network section and a rate of frequency change resulting from the change in the total active power in the network section.

8. The meth

Assignees

• Wobben Properties Gmbh

Inventors

• Brombach Johannes

Classifications

• H02J2101/28

  Wind energy · CPC title

• F03D7/048 Primary

  controlling wind farms · CPC title

• H02J2300/28

  Electricity · mapped topic

• H02J3/381 Primary

  Dispersed generators · CPC title

• F03D7/0284

  in relation to the state of the electric grid · CPC title