Pulse width modulated series resonant converter

A pulse-width-modulated (PWM) extension of the series resonant converter is presented which reduces the dead time and improves the modulation strategy of this type of converter. With the addition of one thyristor and one diode to the 12 thyristors of a series resonant converter, pulses of link current of arbitrary width can be created. Simulations show that good waveform quality can be achieved, and experimental results also show a reduction in the effective dead time. The proposed control scheme has the following advantages over previous methods: inverter switching and external PWM signals can be synchronized; high-frequency DC link current regulation remains possible, allowing line current power factor control; and device stresses are typically lower than in the normal series resonant DC link converter when a PWM technique is employed