Protection scheme switch-timing for doubly-fed induction generator during fault conditions

This paper discusses the detailed switch-timing for converter protection schemes of doubly-fed induction generator (DFIG) to enhance the fault ride-through (FRT) capability. A new combined protection scheme with crowbar and series dynamic resistor (SDR) is used as proposed in former papers. Protection resistance values are calculated after the analysis of rotor fault current for practical application. The protection switching and rotor high current reduction performance are simulated with PSCAD/EMTDC. Fault ride-through performance including the reactive power supply, torque fluctuation and rotor speed with crowbar and series dynamic resistor are also shown. The proposed switch-timing scheme can reduce the time for fault ride-through, hence improving the DFIG fault ride-through performances.