Photovoltaic Inverters in µ-Scale

Inhalt:
Since the early 1990s Photovoltaic (PV) inverters have been developed and manufactured. The sum of all PV power systems, installed worldwide over the last years, reaches 178 Giga Watt peak (GWp). Most of them are equipped with PV central and string inverters. But also since the 1990s so called PV micro inverters, which are suitable for only one PV module, are under development and on the market. Meanwhile the success of this type of PV inverter increases especially in the northern part of America. PV micro inverters are confronted with specific requirements in comparison to the both other types. This results in different technical solutions. The following paper discusses requirements, topologies and design of PV micro inverters. The discussion bases on former works in the field of central and string inverters and an analysis of state-of-the-art PV micro inverter with an AC output power range between approximately 200 W and 300 W from different manufacturers.