Design of a Highly Efficient Microinverter

Abstract

This paper proposes a grid-tied single-phase photovoltaic (PV) microinverter consisting of five-level four-switch (5L-4S) DC-AC converter fed by an isolated fly-back DC-DC converter. The microinverter utilizes a split-coil inductor to produce five levels of pulse width modulation (PWM) compared to the three levels of PWM using conventional four-switch topologies. These implementations reduce losses by up to 39% compared to a conventional topology. The results show that the proposed design improves performance throughout the switching frequency spectra with various loads. The theoretical expectations are validated with simulation and experimental results.