High Voltage Ride-Through Control Strategy of Doubly-Fed Induction Generator Based Wind Turbines With A Series Grid-Side Converter

Based on the advantages of doubly-fed induction generator(DFIG)-based wind turbine with a series grid-side converter(SGSC),this paper studies a control strategy for high voltage ride through(HVRT) operation for such a DFIG system.During grid voltage symmetrical swell fault,with the effective control of the SGSC,the DFIG stator terminal voltage can be kept invariable,which suppresses the transient DC component of the stator's flux.As a consequence,the over-current and over-voltage of DFIG can be eliminated,and the power and electromagnetic torque fluctuations of DFIG can be suppressed.Furthermore,by considering the current rating of the converters,the proposed strategy can supply the transient reactive power support for the grid by controlling rotor side converter(RSC)and parallel grid side converter(PGSC) respectively.The simulation results indicate that the proposed strategy can achieve the HVRT operation for the DFIG system during grid voltage symmetrical swell fault,in the meanwhile,the transient reactive power support can be provided to recover the grid voltage.