Optimal DFIG converter protection design under different controllers

To enable wind turbine and the power converter have the ability to protect itself without disconnection to power grids during the fault, protection for crowbar and chopper should be designed properly. Optimal resistors value of crowbar and chopper are calculated under PVdq controller and Fmac controller according to the proposed index which embody the effect of rotor current, reactive power, converter capacitor voltage and the electrical torque. Simulation results obtained by using PSCAD show that DFIG should be designed with different optimal crowbar and chopper resistors under different controllers. Moreover, DFIG with Fmac controller has better fault ride-through capability than that with PVdq controller