Research On The Maximum Power Point Tracking And Low Voltage Ride-Through Control Of Wind Power Generation System With DFIG

Variable speed constant frequency wind turbine driven by DFIG is one of the two dominant types of wind turbine units.The MPPT and LVRT controls and performances of it are important to the utilisation efficiency of wind energy and the stability of the power grid.The theory and control strategies of maximum power point tracking of variable speed constant frequency wind power generation system with doubly-fed induction generator were firstly investigated on the basis of analyzing the model and performances of DFIG and the air motion characteristics of wind turbines.The performances of three control modes for MPPT including speed control,torque control and power control mode were simulated and compared.The second focus was on the low voltage ride-through control strategies of the DFIG. The transient performances of the DFIG and shortcomings of Crowbar protection were studied,Grid side converter transient voltage control and a coordination control strategy of Crowbar protection,transient voltage control of both converters were proposed as well.Detailed system models were established and the simulation results verified the control strategies are effective.