Study on Low Voltage Ride Through Capability for DFIG Based on Combination Protection Scheme

If wind turbine in large scale wind farms cuts out successively due to voltage drops caused by power failure,system stability will be affected.To ensure the safety reliability of power grid,it is required that the widely used double-fed induction generator(DFIG) should have low voltage ride through(LVRT) capability,which means DFIG should remain on during the low voltage.On the basis of analyzing traditional Crowbar protection circuit in depth,the combination protection scheme and corresponding control strategy are proposed in this paper.Simulation model of wind farm connected to grid is built by Matlab/ Simulink platform,simulation results show that the proposed combination protection scheme can effectively improve the low voltage ride through capability of DFIG.