A novel modulation method for three-phase inverter with pausable switching during arbitrary periods in an arbitrary phase

This paper proposes a novel modulation method for three-phase inverters used in interior permanent magnet synchronous motor (IPMSM) drives. The method can pause the switching during arbitrary periods in an arbitrary phase by changing zero voltage vector ratio, unlike conventional variable switching pause period PWM, which can only pause the switching of one phase while the modulation waveforms of the other two phases are uniquely determined. This paper shows through simulation that the proposed method can pause the switching of arbitrary phases during arbitrary periods. The effectiveness of the proposed method is also demonstrated in an experiment with actual equipment. The inverter efficiency of the proposed method improved by 3.4 percentage points, while the motor efficiency worsened by 0.43 percentage points compared to SVPWM.