Uninterrupted Operation of Doubly-Fed Induction Generator based Wind Turbine during Network

摘要

The proportion of the capacity of the large on-grid wind turbines to transmission networks is increasing rapidly. During the light degree network fault, it is required that wind turbines have certain self-adaptive ability, the wind turbines can operate uninterruptedly and continue to supply the power to network to help the recovery of network fault. Voltage sags is the most common fault of network. This paper mainly discusses the method to improve the uninterrupted operation ability of doubly-fed induction generator (DFIG) based wind turbine under voltage sags. First the simulation model of DFIG system under the network fault is developed. The restricted factors of uninterrupted operation of DFIG under network fault are output current of rotor side PWM converter and voltage of DC line. Then the conventional vector control schemes are improved in order to reducing the current shock of rotor and maintaining constant voltage of DC line. Finally, the simulation of the improved vector control schemes are done, the simulation result verifies the control scheme is effective.