Drive-train torsional vibration suppression of large scale PMSG-based WECS

This paper provides a systematic analysis of the large scale PMsG(permanent magnet synchronous generator)-based WECS(wind energy conversion system)torsional vibration problem under MPPT(maximum power point tracking)control and constant power control.This is from the perspective of SSo(sub-synchronous oscillation),SSH(sub-syn-chronous harmonics)and forced torsional vibration.The cause of SsO is the negative total system damping,weak-ened by the constant power control.The system is susceptible to inducing SSH in the grid current and voltage in the under-damped condition.To effectively suppress the torsional vibration of PMSG-based WECS,a stiffness compensa-tion control strategy based on adaptive damping is proposed.The results show that SSo,SSH and the forced torsional vibration can be suppressed at the source using the proposed suppression strategy.