Active Damping Control for LCT-Filtered PMSM Resonance Suppression Based on Two-Variable Feedback with Inverter Current and Motor Voltage

The new inductor-capacitor-trap (LCT) filter can further suppress high-frequency current harmonics around the switching frequency, so it is important for the permanent magnet synchronous motor (PMSM); however, resonance problems caused by the LCT filter will affect system stability. Active damping is essential to suppress the system resonance. However, with the traditional damping schemes, such as capacitor current feedback (CCF) control, the damping effect and the dynamic response of the LCT-filtered PMSM are difficult to improve simultaneously. In this article, based on the inverter current and motor voltage, a novel two-variable feedback active damping method for the LCT-filtered (TVF-LCT) PMSM is proposed to enhance the damping effect with fast dynamic performance. The TVF-LCT damping parameters are designed; moreover, the stability, damping effect and dynamic performance of the proposed TVF-LCT damping current loop are analyzed. With the undamped LCT, traditional CCF-LCT, and the proposed TVF-LCT damping schemes, the comparative experimental results verify the effectiveness of the proposed TVF-LCT damping scheme.