US 12,407,287 B2
Generator power peak limiting in virtual synchronous machine wind turbine
Torsten Lund, Fredericia (DK); John Godsk Nielsen, Hornslet (DK); and Esmaeil Ebrahimzadehveshareh, Aalborg (DK)
Assigned to VESTAS WIND SYSTEMS A/S, Aarhus N (DK)
Appl. No. 18/723,359
Filed by VESTAS WIND SYSTEMS A/S, Aarhus (DK)
PCT Filed Dec. 15, 2022, PCT No. PCT/DK2022/050284
§ 371(c)(1), (2) Date Jun. 21, 2024,
PCT Pub. No. WO2023/117004, PCT Pub. Date Jun. 29, 2023.
Claims priority of application No. PA202170656 (DK), filed on Dec. 22, 2021.
Prior Publication US 2025/0062709 A1, Feb. 20, 2025
Int. Cl. H02P 21/00 (2016.01); F03D 7/02 (2006.01); H02P 21/05 (2006.01); H02P 21/18 (2016.01); H02P 21/22 (2016.01); H02P 101/15 (2016.01); H02P 103/20 (2016.01)
CPC H02P 21/22 (2016.02) [F03D 7/0284 (2013.01); H02P 21/05 (2013.01); H02P 21/18 (2016.02); F05B 2270/1033 (2013.01); F05B 2270/337 (2013.01); H02P 2101/15 (2015.01); H02P 2103/20 (2015.01)] 15 Claims
OG exemplary drawing
 
1. A method for limiting generator loads in a wind turbine comprising a power converter with a line side inverter arranged to supply power to a power grid, the method comprising:
determining a maximum grid current value based on a measured generator load and a limit function which sets an upper maximum grid current value and a lower maximum grid current value such that (i) the maximum grid current value moves towards the lower maximum current value if generator load is greater than a maximum generator load and (ii) the maximum grid current value moves towards the upper maximum current value if the generator load is smaller than the maximum generator load or is smaller than a low maximum generator load;
determining a virtual impedance value based on a current difference between a current magnitude associated with a grid current and the maximum grid current value, where the virtual impedance value comprises a virtual resistance value;
determining a virtual voltage drop over the virtual impedance value based on the virtual impedance value and the grid current;
determining a virtual grid power based on (i) the virtual resistance value and the grid current or (ii) the grid current and a voltage magnitude reference for a desired grid voltage or a desired reactive power to be generated by the line side inverter;
determining a virtual synchronous machine angle based on a power reference for a desired power output of the power generating unit and the virtual grid power; and
determining a voltage reference for controlling the line side inverter to generate power based on the virtual synchronous machine angle, the virtual voltage drop, and the voltage magnitude reference.