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

The importance of efficiency in photovoltaic (PV) inverter applications makes the topology selection as the critical first step. Due to the low efficiency concern, flyback converter is not the preferred topology in kilowatt range in spite of its galvanic isolation, low cost, and small size advantages. Therefore, the objective of this research is to change the perception 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-efficiency flyback transformers with extremely low leakage inductance and by implementing a prototype with the lowest parasitic components. As a result, the efficiency of the experimental inverter is measured as 95.82 %. Moreover, the low cost and small size objectives are also maintained with very good grid side performance. Consequently, the experimental results demonstrated that the flyback-converter-topology-based inverters can be successfully implemented at high power with high efficiency and with high commercial value.