Study on transient performance of doubly fed induction generator with crowbar during three-phase voltage dips

Transient analysis is key point for studying on Doubly-Fed Induction Generator (DFIG) for Low Voltage Ride Through(LVRT). Lots of assumptions and approximations are made in conventional analysis, such as ignored stator resistance or rotor fixed voltage. It cannot accurately describe the transient performance.

In this paper, according to the mathematical model of DFIG, transient characteristic is analyzed with retaining the effect of stator resistance and rotor current. The precise expression of stator and rotor current is given. And the relationship between the value of the crowbar resistance and the rotor current, the rotor voltage, the decay time constant is discussed in the paper too. It provides a theoretical basis for crowbar resistance selected and LVRT strategy.