A Notch Filter-Based Active Damping Strategy for Resonance Mitigation in LC-filtered SPMSM

With the application of new high-frequency switching devices in motor variable frequency drives, the reflected overvoltage caused by long-line effect has become more and more serious. In order to solve the problem, a LC output filter can be employed. However, the motor inductance together with LC filter will form LCL network and bring the inherent resonance risk. What is worse, stator inductance of SPMSM is relatively large and varies with rotor rotation, which leads to a shift of resonance frequency, and is adverse to the fixed-frequency active damping method. Therefore, in order to guarantee a normal operation of SPMSM drive system, the stability of whole system will be deeply studied in this paper. Meanwhile, a novel active damping strategy based on notch filter will be proposed to mitigate the resonance, and the effectiveness of the proposed method in the LC-Filtered SPMSM with converter-current feedback control system is verified by simulation.