Regenerative dV/dt Filter Topology for Motor Drives

A regenerative inverter output dV/dt filter topology is proposed for a Wide-bandgap (WBG) device-based motor drive system. This work eliminates the requirement of a passive resistor in an LCR filter topology with a GaN-based full-bridge converter. The proposed unit mimics the operation of the passive resistor by recycling the energy of the filter path. The proposed active filter only processes the high-frequency power, so the current ratings of the devices in the regenerative filter are significantly lower compared to the main converter's switches. This regenerative active resistor allows the use of a lower filter inductor in the series path, reducing the overall filter size. As a result, the proposed regenerative ultra-low loss dV/dt filter minimizes the stress on the motor insulation and improves the motor drive system's efficiency and power density. Detailed MATLAB/Simulink-based simulation results are provided to validate the performance of the proposed filter topology. An experimental double pulse test (DPT) results have been performed to validate the operation of the proposed concept.