A review of inverter topologies for single-phase grid-connected photovoltaic systems

The concept of injecting photovoltaic power into the utility grid has earned widespread acceptance in these days of renewable energy generation & distribution. Grid-connected inverters have evolved significantly with high diversity. Efficiency, size, weight, reliability etc. have all improved significantly with the development of modern and innovative inverter configurations and these factors have influenced the cost of producing inverters. In this review work, all aspects covering standards and specifications of single-phase grid-connected inverter, summary of inverter types, historical development of inverter technologies, classifications of inverter topologies are presented in a systematic manner. Finally, some transformer-less topologies based on bridge configuration and multilevel concept, and some soft-switching inverter topologies are remarked as desirable with respect to high efficiency, low cost, and compact structure. Areas of further works including use of advanced semiconductor devices, improvement of de-coupling capacitor etc. are also pointed out to draw attention of inverter designer for further increase of efficiency and lowering the cost.