Study on converters for doubly fed induction generator based wind power generation system

Doubly-fed induction generator (DFIG) based wind power generation is connected to power grid via an electrical conversion system which consists of two back-to-back connected voltage source converters, i.e., rotor side converter (RSC) and grid side converter (GSC). Both converters have the same topology and working principles with different functions during operation. Hence, the characteristics and construct of three-phase voltage source PWM converters were first analyzed. Further, some auxiliary services with the converters were investigated such as voltage control capability, reactive power compensation capability, fault ride through capability and active harmonic filtering capability and so on, in respond to the stringent grid codes nowadays. An active harmonic filtering approach was presented. Simulation results illustrate good performance of the proposed system and control strategies.