A Half-Bridge Hybrid Resonant Inverter with Novel Pulse Phase Modulation Control

It is necessary that the phase angles of the inverter output voltages be controlled to minimize the circulating current in a high frequency AC (HFAC) power distribution system, where multiple resonant inverters are paralleled to the high frequency AC bus through connection inductors. However, the phase angle of the high frequency resonant inverters output voltage can not be controlled with conventional phase shift modulation or pulse width modulation. The phase angle is a function of both the phase of the gating signals and the impedance of the resonant tank. In this paper, we proposed a pulse phase modulation (PPM) concept for the resonant inverter, so that the phase angle of the resonant inverter output voltage can be regulated. The PPM can be used to minimize the circulating current in a multiple resonant inverter system. The mechanism of the PPM was explained and analyzed. The PPM-controlled resonant inverter was experimentally verified in two two-stage resonant inverters of 100 W, 500 kHz