Analysis of Soft Switching Conditions for Push-Pull Current Type Bidirectional DC/DC Converter

Abstract

This article first introduces the working principle of a push-pull current type DC/DC converter, analyzes the transient working process of the converter within one working cycle of the control signal, and draws the relevant waveforms of the main parameters of the circuit; Secondly, equivalent circuits were established for each switch in the circuit to achieve soft switching. At the same time, due to the isolation of the DC/DC converter using parasitic parameters of the converter for resonance, the soft switching conditions of the switch were achieved. The main parameters of the resonance process were the parasitic capacitance of the switch and the transmission inductance of the converter. Therefore, based on the soft switching implementation process of each switch, the influence relationship between the parameter design of parasitic capacitance and transmission inductance on the soft switching is derived; Finally, the software simulation and prototype experimental platform were built to verify that the derived soft switching conditions can serve as the theoretical basis for the parameter design of push-pull current type DC/DC converters.