A PAC based three-phase zero-voltage soft-switching PWM converter

A novel based on phase and amplitude control (PAC) three-phase zero-voltage soft-switching (ZVS) PWM converter is presented. In resonance period for the ZVS converter the equivalent circuit, running conditions, the control signals and action waveforms is illustrated. The modulation method adopts the saw-tooth carrier with alternative positive and negative slopes, comparing with the conventional triangular carrier it brings advantages for system. A phasor adjusting method is proposed and the low-frequency math model of system is built. The configuration of control system and its operational principle are introduced. Experimental study with a 0.75 kW device shows that both in the rectifying and regenerating modes, the system can realize ZVS control and unity power factor, providing sinusoidal line currents, so it reaches the aim of restraining electromagnetic interference (EMI) and harmonic pollution.