High-efficiency design of a grid-connected PV inverter based on interleaved flyback converter topology

Abstract

The importance of efficiency in photovoltaic (PV) inverter applications makes the topology selection as thecritical first step. Due to the low efficiency concern, flyback converter is not the preferred topology in kilowatt range inspite of its galvanic isolation, low cost, and small size advantages. Therefore, the objective of this research is to change theperception in favor of flyback converter by designing a flyback-topology-based PV inverter at 2.5 kW with high efficiency.The enhancement in efficiency is achieved mainly by using silicon carbide switching devices, designing ultrahigh-efficiencyflyback transformers with extremely low leakage inductance and by implementing a prototype with the lowest parasiticcomponents. As a result, the efficiency of the experimental inverter is measured as 95.82%. Moreover, the low cost andsmall size objectives are also maintained with very good grid side performance. Consequently, the experimental resultsdemonstrated that the flyback-converter-topology-based inverters can be successfully implemented at high power withhigh efficiency and with high commercial value.