A hybrid power plant and a method for controlling a hybrid power plant

Patent metadata

Field	Value
Publication number	US-2021281079-A1
Application number	US-201917259431-A
Country	US
Kind code	A1
Filing date	Jun 24, 2019
Priority date	Jul 9, 2018
Publication date	Sep 9, 2021
Grant date	—

Abstract

The invention relates to a hybrid power plant with a plurality of energy assets comprising several renewable power generating units, preferably in turn comprising wind turbines and/or solar power units, and an energy storage unit, such as battery energy system. A power plant controller receives information indicative of a power limitation from the energy storage unit, and dynamically modify the active power set points by corresponding weighting factors according to the capabilities of the respective energy assets in response to this power limitation so as to produce active power from the hybrid power plant. The invention may compensate for this power limitation by modifying correspondingly the active power set points of the hybrid power plant according to the capability of the energy assets so as to maintain a desired power production, and maintain a sufficiently smooth ramp rate when changing a parameter related to the power production.

First claim

1 . A hybrid power plant connected to an associated electrical grid for producing power to said electrical grid, the hybrid power plant comprising a plurality of energy assets, the plurality of energy assets comprising:
a first renewable power generating unit, said first renewable power generating unit comprising a plurality of wind turbine generators, a second renewable power generating unit, said second renewable power generating unit comprising a plurality of solar power units, and an energy storage unit, a battery energy storage system, said energy storage unit being capable of storing energy from said first and second renewable power generating units, and delivering power to said electrical grid when required,
wherein the hybrid power plant further comprises a power plant controller arranged to communicate with the plurality of energy assets, the power plant controller being arranged for receiving an active power reference and correspondingly distribute active power set points to the plurality of energy assets, and
wherein the power plant controller is further arranged to receive information indicative of a power limitation from the energy storage unit, and dynamically modify the active power set points by corresponding weighting factors according to the capabilities of the respective energy assets in response to said power limitation so as to produce active power from the hybrid power plant accordingly.

2 . The hybrid power plant according to claim 1 , wherein the hybrid power plant further comprises:
a module for deriving an estimated value for electrical losses in the hybrid power plant; a module for deriving a measured value for electrical losses in the hybrid power plant, based on a difference between an aggregated power production from the plurality of energy assets and a power measurement at a point of common coupling, and a regulator arranged to apply the estimated value for electrical losses and the measured value for electrical losses in an active power control loop in the power plant control, the active power control loop being arranged to control an active power production of the hybrid power plant at the point of common coupling.

3 . The hybrid power plant according to claim 1 , wherein the information indicative of power limitation comprises a charge and/or discharge limitation from the energy storage unit being a third energy asset.

4 . The hybrid power plant according to claim 3 , wherein the first and second renewable power generating units form a first and a second energy asset, respectively, and, if a power limitation from the third asset results in a difference between the power reference and an aggregated power production from the plurality of energy assets, the power plant controller then being arranged to modify the active power set points of said first (1EA) and a second energy assets by corresponding weighting changing factors being a function of said difference between the power reference and an aggregated power production measured from said first and second energy assets.

5 . The hybrid power plant according to claim 4 , wherein each corresponding weighting changing factor of an energy asset is further a function of the power from each energy asset, preferably based on available power and/or nominal power from each energy asset.

6 . The hybrid power plant according to claim 3 , wherein the active power set point distributed by the power plant controller to the energy storage unit is determined by the capability of the third energy asset resulting from said power limitation in the third energy asset, preferably based on the available power and nominal power from said third energy asset.

7 . The hybrid power plant according to claim 3 , wherein the hybrid power plant is operated in a mode, wherein the power plant controller distributes the active power set point to the energy storage unit, said active power set point being determined externally to the hybrid power plant.

8 . The hybrid power plant according to claim 1 , wherein the hybrid power plant is operated in a curtailment reduction mode, wherein the power plant controller is operated so as to reduce, or limit, curtailment of the first renewable power generating unit,
preferably one, or more, wind turbine generators of said plurality of wind turbine generators, and curtailment of the second renewable power generating unit,
preferably one, or more, solar power units of said plurality of solar power units,
by charging accordingly the energy storage unit.

9 . The hybrid power plant according to claim 1 , wherein the hybrid power plant is in a constant power control mode, wherein the power plant controller is operated so as to maintain a substantially constant power level from the hybrid power plant according to the active power reference particularly comprising discharging accordingly the energy storage unit.

10 . The hybrid power plant according to claim 1 , wherein the hybrid power plant is in a frequency control mode, wherein the power plant controller is operated so as to balance a frequency change by a corresponding power produced from the hybrid power plant particularly comprising discharging, or charging, the energy storage unit.

11 . The hybrid power plant according to claim 7 , wherein the hybrid power plant is operated in a plurality of modes for the power plant controller, and wherein at least one mode among the plurality of modes is prioritised over the remaining modes.

12 . The hybrid power plant according to claim 11 , wherein said curtailment reduction mode, said constant power control mode or said frequency control mode, has priority over a mode wherein the active power set point is determined externally to the hybrid power plant.

13 . A method for controlling a hybrid power plant, the hybrid power plant being connected to an associated electrical grid for producing power to said electrical grid, the hybrid power plant comprising a plurality of energy assets, the plurality of energy assets comprising:
a first renewable power generating unit, said first renewable power generating unit comprising a plurality of wind turbine generators, a second renewable power generating unit, said second renewable power generating unit comprising a plurality of solar power units, and a battery energy storage system, said battery energy storage unit being capable of storing energy from said first and second renewable power generating units, and delivering power to said electrical grid when required, the method, comprising:
controlling a power plant controller arranged to communicate with the plurality of energy assets, the power plant controller being arranged for receiving an active power reference and correspondingly distribute active power set points to the plurality of energy assets, and
receiving information indicative of a power limitation from the battery energy storage unit, and dynamically modify the active power set points by corresponding weighting factors according to the capabilities of the respective energy assets in response to said power limitation so as to produce active power from the hybrid power plant accordingly.

14 . A power controller for controlling an associated hybrid power plant connected to an associated electrical grid for producing power to said electrical grid, the hybrid power plant comprising a plurality of energy assets, the plurality of energy assets comprising:
a first renewable power generating unit, said first renewable power generating unit comprising a plurality of wind turbine generators, a second renewable power generating unit, said second renewable power generating un

Assignees

• Vestas Wind Sys As

Inventors

• Valcan Dumitru-Miha

Classifications

• H02J2101/28

  Wind energy · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J3/48

  Controlling the sharing of active power · CPC title

• F03D7/048 Primary

  controlling wind farms · CPC title

• F03D9/255

  connected to electrical distribution networks; Arrangements therefor · CPC title