Direct power control of DFIG wind turbines for low voltage ride-through

This paper proposes a direct power control strategy for Doubly Fed Induction Generators (DFIGs) to ride through grid voltage dips, based on proportional integral resonant (PIR) controllers. The control domain of the proposed strategy is also analyzed, which indicates the necessary of additional protection implement such as a crowbar. Then a coordinated control scheme, with a demagnetization method and a crowbar control strategy, is proposed to enhance the low voltage ride-through (LVRT) performance. To validate the proposed method, a digital signal processor (DSP) and complex programmable logic device (CPLD) based 7.5KW experimental prototype is built up. Experimental results are provided to verify the theoretical findings, which show the effectiveness of the proposed control scheme.