Ride through of grid faults for PMSG based wind energy conversion systems

Permanent magnet Synchronous Generators (PMSG) are becoming popular for wind energy conversion systems (WECS) nowadays due to the possibility of gearless operation even in grid connected mode. However, these systems have serious problems during fault conditions such as over speeding of the generator speed and undue increase in the DC link capacitor voltage. This paper proposes a complete coordinated control of the generator and the power electronic converters to achieve fault-ride-through (FRT) capability. The analysis and simulation of a PMSG based WECS is presented here for normal working conditions as well as for fault conditions. The uniqueness of the model includes de-loading of the generator via machine side converter, active and reactive power control through grid side converter to support voltage control during fault. The simulation results prove the capability of the system to harness maximum power during normal conditions and to achieve FRT during a severe three-phase fault.