Novel resonant pole soft-switching inverter for brushless DC motor

To achieve high efficiency and the high frequency and improve reliability in Brushless DC Motor (BLDCM) system with limited energy, a novel Resonant Pole Voltage-Source-Inverter (VSI) was proposed for BLDCM, which has advantages of Resonant Pole Inverter (RPI) and Pulse Width Modulation (PWM). Soft switching operation of switch devices in inverter was realized by adding auxiliary resonant unit from three output ends to DC link. Auxiliary resonant switch was turned on under Zero Current Switching (ZCS) and turned off under Zero Voltage Switching (ZVS). Resonant time is short and resonance only uses an inductor, so resonant unit consumes little power. Mathematic analysis and simulation was performed for novel inverter, and the simulation results are consistent with the theoretical analysis.