Active Damping Circuit for a Soft-Switching ARCP Motor Drive

In this paper, an active damping method to mitigate voltage and current oscillations in a soft-switching motor drive e.g. auxiliary resonant commutated pole (ARCP) inverter is proposed. While soft-switching inverters are popular due to low loss and ability of operating at high switching frequency, they also bring oscillation issues. Such issues can be well mitigated by implementing proper damping methods. The proposed active damping method has advantages of low power loss, load-independence and fast settling time over conventional passive damping method. The proposed method is demonstrated in a single-phase ARCP inverter. The primary oscillation loop in ARCP inverter is described, the operating principle and control scheme of the proposed active damping method is analyzed. A simulation model was built to explore the characteristics of active damping method. A 750V(dc)/200A single phase ARCP inverter prototype is used to validate the effectiveness of the proposed method and various testing results show the superiority of the proposed active damping method over conventional passive damping method.