APWM converter with primary-series and secondary parallel connection for DC micro-grid system

A soft switching DC converter in DC micro-grid system applications is studied in this paper. The employed converter has three half-bridge circuits with series and parallel connection so as to reduce voltage rating of power switches and current rating of rectifier diodes. Therefore, MOSFET with low voltage stress and low conduction resistance can be utilized. Asymmetric PWM scheme is used to achieve low switching losses and high circuit efficiency. Input flying capacitors are used in the primary side to balance input split voltages. The voltage stress of each power switch is clamped at one third of input voltage. Finally, experiments are provided to demonstrate the circuit performance.