Recent developments in topologies of single-phase buck-boost inverters for small distributed power generators: an overview

Unique requirements for small distributed power generation (DG) systems include low cost, high efficiency, and tolerance for an extremely wide range of input voltage variations. The inverters in such systems not only perform functions such as normal DC-AC conversion, output power quality assurance, various protections and system controls, but also meet these requirements, which have driven the inverter development toward simpler topologies and structures, lower component counts, and tighter modular design. Both single-stage and multiple-stage inverters have been developed for power conversion in DG systems. While single-stage inverters enjoy simple structure and low cost, they suffer from a limited range of input voltage variations and often a compromised system performance. On the other hand, multiple-stage inverters can accept a wide range of input voltage variations, but assume high cost, complicated structure, and low overall efficiency. This paper presents an overview of the development in the single-phase inverters for small distributed power generators with various circuit topologies and discussions as well as the identification of recent development trends.