Study of Adjustable Discontinuous Pulse Width Modulation (ADPWM) Based on Switching Transient Inverter Loss Algorithm

In order to improve the electric vehicle endurance mileage and output characteristics of motor, the optimization of inverter loss and motor current ripple reduction are considered. Aiming at high inverter loss of traditional SVPWM and high current ripple of DPWM, an adjustable discontinuous pulse width modulation(ADPWM) is proposed, whose clamping angle α and clamping phase angle θ are variable. In order to accurately calculate the inverter loss, a switching instantaneous inverter loss model is proposed, and the ADPWM inverter loss and current total harmonic distortion(THD) was studied based on Simulink modeling and simulation. The simulation and experiment results show that the experiment can be accurately reflected by Simulink model; The inverter loss can be reduced by 15%-25% by introducing ADPWM while the current distortion rate is low. With the clamping angle α increasing, the inverter loss decreased significantly. The inverter loss and motor output characteristics are effectively balanced, with setting α ranging from 40° to 55° in high speed and low load condition or setting α =55° in high speed full load condition. When α is a constant, the motor current characteristics are improved and inverter loss is reduced by the appropriate advanced clamping phase angle(-15°<θ<-5°). The continuous variable seamless conversion between different PWM methods can be realized by ADPWM.