Analysis of the interleaved APWM converter with less power switches

This paper presents an interleaved converter to share the load current and achieve soft switching feature on switches. There are two modules in the proposed converter. Two modules are operated with the interleaved PWM to achieve load current sharing, reduce the current ripple on the output capacitor, and regulate the output voltage. In each module, there are two circuit cells to achieve parallel operation. Only two power switches are required in each converter module to realize the parallel operation and equally share the output current. Each circuit cell is controlled using the asymmetrical PWM (APWM) scheme to realize the ZVS turn-on for power switches. The leakage inductance of the transformer is employed to realize the ZVS feature during the transient interval. The voltage stress of each switch is clamped at the input source voltage. Instead of the conventional interleaved converter, each power switch in the proposed converter can achieve both functions of forward converter for one cell and active clamp circuit for the other cell at the same time. Compared with the conventional parallel converters with four circuit cells, the proposed converter has less power switches, less circuit complexity and lower cost. The system analysis, operation principle and design consideration are presented. Finally experiments based on a laboratory prototype with rated 480 W are provided to verify the effectiveness of the proposed converter.