Improvement of Fault Ride through Capability of Doubly-Fed Induction Generator Wind Turbines with Hysteresis Controller

Abstract

Much attention has been received by the fault ride through (FRT) capacity of doubly fed induction generator (DFIG) wind turbines, due to its important influence on the large penetration of wind turbines into power system. Conventional control for a DFIG has tended to adapt a nested inner- and outer-loop control based on vector control techniques. In general, inner loop controller to regulate the rotor current is implemented by a proportional-integral (PI) regulator. In the paper, the PI regulator will be replaced with a hysteresis controller in order to improve the performance of FRT of DFIG wind turbines when they are subjected to a dip of grid voltage. Hysteresis controller has fast transient response, simple control structure, and robustness to the machine parameters variations and consequently the proposed scheme can significantly improve the FRT capacity of DFIG wind turbines. The FRT capability of DFIG-based wind turbines with the proposed scheme is validated by the simulation using the dedicated power system analysis tool PSCAD/EMTDC.