To address the challenge of insufficient primary frequency regulation in grid-connected wind turbines during frequency disturbances
a control strategy is proposed that integrates energy storage on the DC side of direct-drive wind turbines. Firstly
this strategy incorporates a virtual synchronous generator (VSG) control method in the grid-side converter to deliver immediate power support during frequency fluctuations. Furthermore
the addition of a DC-side energy storage system ensures rapid stabilization of the DC voltage to its reference value during frequency dips
allowing the machine-side converter to maintain stable operation in maximum power point tracking mode. Meanwhile
the grid-side converter enhances power output
enabling the wind turbine to perform primary frequency regulation. The proposed approach is validated using simulations of a single-machine system and a four-machine two-area system in Matlab/Simulink. Results indicate that
compared to traditional grid-connected wind turbines
this method increases power output by 24.2% and reduces frequency drop depth by 60% during sudden load changes
demonstrating superior primary frequency regulation capabilities.
TAYYEBI A, GROß D, ANTA A, et al.Frequency stability of synchronous machines and grid-forming power converters[J]. IEEE journal of emerging and selected topics in power electronics, 2020, 8(2): 1004-1018.