A Band-Stop-Type dv/dt Filter for Terminal Overvoltage Mitigation of SiC Motor Drives

The motor terminal overvoltage caused by high dv/dt of devices remains a challenge for silicon carbide motor drives. As a solution, this paper proposes a passive dv/dt filter based on the overvoltage analysis in the frequency domain. The proposed filter adopts an innovative band-stop structure with a parallel connected R-L-C circuit. The R provides damping and realizes impedance matching with the cable. The LC creates a parallel resonance at a specific frequency for the high-impedance state with a small inductance to mitigate the reflected wave oscillation and obtain selective filtering. The experimental results show that this passive filter can realize similar effects of active filters, while has lower loss and smaller volume than other passive filters.