Topology Morphing Control of Low-Cost PV Microconverters

Abstract

The focus is on the low-cost photovoltaic microconverter based on the single-switch quasi-Z-source DC-DC converter topology. It is demonstrated that its performance can be significantly improved by using the topology morphing control. Unlike its counterparts, this topology allows for several topology morphing control implementations – either using a combined energy transfer or a reconfigurable rectifier. These two approaches are compared in terms of power losses estimated based on the simulated voltage and current waveforms. The obtained results are discussed in terms of efficiency improvement and converter mode transition points. Discussion regarding differences in the mechanism of losses is provided.