A push-pull DC-AC high frequency power electronics transformer for photovoltaic applications

Abstract

This paper presents a novel DC-AC inverter based on a high frequency power electronic transformer. It makes use of an adapted push-pull converter on the primary side of the transformer to apply a high frequency alternating voltage. This keeps the transformer flux low and transformer size small, reducing the cost of materials but at the same time keeping the power density high. The secondary side is a set of two bi-directional switches that synthesize the desired output voltage in a cycloconverter manner, helping to reduce the total harmonic distortion. A state space control strategy and commutation of the secondary side is also presented. The topology and control strategy has been confirmed with simulation results.