Design and implementation of a push-pull phase-shifted bi-directional inverter with a dsPIC controller

Abstract

This paper presents design and implementation of a bi-directional inverter, including a high frequency transformer, a push-pull switch configuration at the dc side, a cycloconverter at the ac side, and a dsPIC controller. The dc/ac conversion is achieved with a phase-shifted control strategy. In addition, this topology also can achieve an ac/dc conversion with the PFC function. In this circuit, the dsPIC realizes almost all functions, including generation of PWM signals, A/D conversion, phase shift, circuit protection, and PFC during ac/dc conversion. The proposed bi-directional inverter can reduce weight, size and volume significantly as compared to a conventional low frequency transformer approach. Experimental results obtained from a prototype with a dc side voltage of 48V, an ac side voltage of 110Vrms, and power rating of 500W have verified its feasibility.