Enhanced current reference generation for PMSG-based wind systems using modified delayed signal cancellation

Permanent magnet synchronous generator (PMSG)-based wind systems are highly sensitive to grid-voltage unbalances, which generate negative-sequence voltages and currents and lead to pronounced double-frequency oscillations in output power, grid currents, and DC-link voltage. Existing mitigation strategies, typically based on dual vector control or sequence-component compensation, often require multiple controllers, increase implementation complexity, and may not simultaneously minimize oscillations in all key variables. To overcome these limitations, this paper proposes a unified reference current generation method that does not rely on dual vector control and is capable of jointly reducing fluctuations in active and reactive power, grid currents, and DC-link voltage. The method computes the optimal reference currents in a systematic manner, enabling coordinated control under unbalanced grid conditions. In addition, a Modified Delayed Signal Cancellation (MDSC) technique is introduced to achieve fast and accurate separation of positive- and negative- sequence components, thereby improving the precision of the generated reference signals. The effectiveness of the proposed approach is validated through comprehensive time-domain case studies on a 1.5 MW PMSG system in the MATLAB/Simulink environment under a variety of unbalanced voltage scenarios. The simulation results demonstrate improved power quality and superior performance compared with conventional control methods. • A simplified reference current generation method removes dual‑vector control and PLLs in PMSG converters under unbalanced grids. • A modified delayed signal cancellation (MDSC) method separates positive and negative sequences with fast response. • The method reduces double‑frequency oscillations in power, grid current, and DC‑link voltage during grid faults. • MATLAB/Simulink simulations of a PMSG confirm improved stability and lower DC‑link voltage ripple under voltage sags. • The approach uses simple PI controllers and an analytical term, enabling low‑complexity real‑time implementation.