# US 2023/0054556 A1 · Methods and systems for power control in a non-exporting mode of operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054556 A1 - Document ID: US20230054556A1 - Status: Published application - Kind: A1 - Application number: 17/881,305 - Filed: 2022-08-04 - Published: 2023-02-23 - Earliest claimed: 2021-08-17 - Assignees: Vestas Wind Systems A/S - Applicants: Vestas Wind Systems A/S - Inventors: Karthikeya Balladi Raghuchandra; Chris Damgaard - Web page: https://patentgrep.com/patent/US20230054556A1 ## CPC - H02J 3/381: {Dispersed generators} - F03D 7/048: {controlling wind farms} - F03D 9/11: storing electrical energy - H02J 3/46: Controlling the sharing of generated power between the generators, sources or networks - H02J 7/34: Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence) - F05B 2260/42: Storage of energy - F05B 2270/32: Wind speeds - F05B 2270/321: Wind directions - H02J 3/388: Arrangements for the handling of islanding, e.g. for disconnection or for avoiding the disconnection of power - H02J 2101/28: Wind energy - Y02E 10/72: Wind turbines with rotation axis in wind direction - Y02E 10/76: Power conversion electric or electronic aspects - Y02E 70/30: Systems combining energy storage with energy generation of non-fossil origin - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - F03D: WIND MOTORS - F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Aspects of the present invention relate to controlling a renewable energy power plant comprising a plurality of wind turbine generators (WTG)s and an energy storage system (ESS). A method includes: controlling the plurality of WTGs to stop generating power, and thereby to enter a non-exporting mode of operation of the renewable energy power plant, during which one or more auxiliary systems of the renewable energy power plant are powered to maintain at least one of the plurality of WTGs in a standby state, operable to start generating power upon demand; wherein the one or more auxiliary systems are powered during the non-exporting mode of operation. ## Claims ### Claim 1 A method of controlling a renewable energy power plant comprising a plurality of wind turbine generators (WTG)s and an energy storage system (ESS), the method comprising: controlling the plurality of WTGs to stop generating power, and thereby to enter a non-exporting mode of operation of the renewable energy power plant, during which one or more auxiliary systems of the renewable energy power plant are powered to maintain at least one of the plurality of WTGs in a standby state, operable to start generating power upon demand; wherein the one or more auxiliary systems are powered during the non-exporting mode of operation by: discharging stored energy from the ESS; detecting when a first energy storage condition is satisfied; operating one or more of the WTGs to start generating power in dependence on detecting that the first energy storage condition is satisfied, the power generated by the one or more WTGs being used to power the one or more auxiliary systems; operating the ESS to recharge using the power generated by the one or more WTGs; detecting when a second energy storage condition is satisfied; and operating the one or more WTGs to stop generating power in dependence on detecting that the second energy storage condition is satisfied. ### Claim 2 (depends on 1) The method of claim 1, wherein detecting that the first energy storage condition is satisfied comprises detecting that at least one of: a discharge period has elapsed; and/or the energy stored in the ESS has reduced to a first threshold state of charge. ### Claim 3 (depends on 1) The method of claim 1, wherein detecting that the second energy storage condition is satisfied comprises detecting that at least one of: a duty period for the one or more WTGs has elapsed; and/or the ESS has recharged to a second threshold state of charge. ### Claim 4 (depends on 3) The method of claim 3, wherein the second threshold state of charge is a maximum charge capacity of the ESS. ### Claim 5 (depends on 1) The method of claim 1, further comprising at least one of: stopping the discharge of stored energy from the ESS when the power generated by the one or more WTGs is greater than, or equal to, the power demand of the one or more auxiliary systems; and/or resuming the discharge of stored energy from the ESS when the power generated by the one or more WTGs is less than the power demand of the one or more auxiliary systems. ### Claim 6 (depends on 1) The method of claim 1, further comprising curtailing the one or more WTGs that are operated to generate the power for recharging the ESS and powering the auxiliary load. ### Claim 7 (depends on 6) The method of claim 6, wherein curtailing the one or more WTGs comprises: determining an average power demand of the one or more auxiliary systems; and determining and dispatching active power set points for controlling the one or more WTGs, the set points being determined based, at least in part, on the determined average power demand. ### Claim 8 (depends on 1) The method of claim 1, further comprising selecting which one or more WTGs of the plurality of WTGs to operate so as to start generating power, wherein the selection is made based on at least one of the following for each WTG: information that is indicative of available power at the WTG; and/or information that is indicative of a fatigue life of the WTG. ### Claim 9 (depends on 8) The method of claim 8, wherein the information that is indicative of available power at the WTG comprises a wind speed and/or a wind direction at the WTG. ### Claim 10 (depends on 8) The method of claim 8, wherein the information that is indicative of the fatigue life of the WTG comprises at least one of: a load cycle history of the WTG; a fatigue limit of the WTG; and/or a load capacity of the WTG. ### Claim 11 (depends on 8) The method of claim 8, wherein the renewable energy power plant is controlled to cyclically discharge the ESS and to recharge the ESS using the selected one or more WTGs, and thereby to power the one or more auxiliary systems during the non-exporting mode of operation. ### Claim 12 (depends on 11) The method of claim 11, wherein, for each successive cycle, the method comprises selecting another one or more WTGs of the plurality of WTGs to operate so as to start generating power. ### Claim 13 (depends on 1) The method of claim 1, further comprising: initiating the non-exporting mode of operation in dependence on entering: an island mode of operation following disconnection of the renewable energy power plant from a power network; and/or a net-zero mode of operation. ### Claim 14 (depends on 1) The method of claim 1, further comprising selectively operating the at least one WTG from the standby state to black-start the renewable energy power plant, and thereby to re-enter a producing mode of operation. ### Claim 15 A power plant controller, comprising: an input/output (I/O) interface; and one or more processors communicatively coupled to the I/O interface and configured to perform an operation for controlling a renewable energy power plant comprising a plurality of wind turbine generators (WTG)s and an energy storage system (ESS), the operation, comprising: controlling the plurality of WTGs to stop generating power, and thereby to enter a non-exporting mode of operation of the renewable energy power plant, during which one or more auxiliary systems of the renewable energy power plant are powered to maintain at least one of the plurality of WTGs in a standby state, operable to start generating power upon demand; wherein the one or more auxiliary systems are powered during the non-exporting mode of operation by: discharging stored energy from the ESS; detecting when a first energy storage condition is satisfied; operating one or more of the WTGs to start generating power in dependence on detecting that the first energy storage condition is satisfied, the power generated by the one or more WTGs being used to power the one or more auxiliary systems; operating the ESS to recharge using the power generated by the one or more WTGs; detecting when a second energy storage condition is satisfied; and operating the one or more WTGs to stop generating power in dependence on detecting that the second energy storage condition is satisfied.