Stator Harmonic Current Suppression for DFIG System Considering Integer Harmonics and Interharmonics

This paper presents a stator harmonic current suppression method for a doubly fed induction generator (DFIG) under the distorted grid voltage with the consideration of integer harmonics and interharmonics. In the proposed control strategy, the stator current incomplete derivation controller instead of the resonant controller or a repetitive controller is employed to eliminate the negative impacts on the stator current caused by the distorted grid voltage. This approach can provide both the good dynamic response and the strong rejection ability against the integer harmonic voltages with the fixed frequency and the interharmonic voltages with the unfixed frequency. Based on the mathematic model of the DFIG, the stator current incomplete derivation feedback is designed in detail. Then, the robustness against the fundamental frequency variations and the DFIG parameter deviations is analyzed. Finally, the experimental results are presented to validate the effectiveness of the proposed control strategy.