An Overview of Photovoltaic Microinverters: Topology, Efficiency, and Reliability

This paper presents an overview of microinverters used in photovoltaic (PV) applications. Conventional PV string inverters cannot effectively track the optimum maximum power point (MPP) of the PV string due to the series configuration (especially, under partial shading conditions). In order to tackle this problem, microinverters make each PV panel operate at its own MPP so that the overall efficiency can be improved. In this paper, a detailed analysis is carried out among commercially-available microinverters in terms of topological structure and operational principle. Moreover, the latest products on the microinverter market and future trends of the microinverters are discussed in terms of efficiency and reliability.