Interleaved two-switch flyback microinverter for grid-tied photovoltaic applications

Abstract

This paper presents a microinverter topology to mitigate the problem of high-voltage transients occurs at switch turn off in single switch flyback microinverters. Voltage transients are caused by the resonance between the transformer leakage inductance and the transistor output capacitance, which results in a high-voltage stress leading to high conduction and switching losses. The proposed topology is configured with interleaved two switch flyback microinverter link to a single phase utility grid. The maximum voltage stress of the switches is limited to the DC input voltage, reducing the switching and conduction losses. For improving efficiency in all power ranges, hybrid control method which controls each phase of microinverter according to output power of microinverter is also applied. The simulation results validate the performance of the presented technique and show excellent promise for utilizing in industrial scale.