Loss Equalization of Unbalanced Three-Phase Inverter by Pulse-Voltage-Injection Two-Phase PWM Using Variable Switching Pause Period

Our research group proposed a variable switching pause period two-phase PWM scheme to equalize switching device losses in unbalance three-phase inverters for long lifespan. However, the three-phase inverters driven by the two-phase PWM scheme provide any current harmonics. To overcome this problem, this report proposes combining the pulse-voltage-injection two-phase PWM scheme with a variable switching pause period. Some experimental results reveal that the proposed PWM scheme equalizes device losses and reduces output current harmonics of an unbalanced three-phase inverter for an inductive load and an induction motor.