New quasi-resonant PWM inverter using two internal voltage-points of DC source

This paper presents a new quasi-resonant PWM inverter which has series-connected batteries as the DC-source. The inverter includes two main switches and two additional switches, and all these devices achieve soft switching operation. Resonant operations are employed only during the commutating intervals, then the circuit behaves as an ordinary PWM inverter except during these intervals. This circuit has the feature of using two internal voltage-points of the DC source. Consequently, the circuit has the advantages of stability, simplicity in control, and high efficiency. The principle of the circuit operation and the experimental results are described in this paper