Photovoltaic inverter with a novel cycloconverter for interconnection to a utility line

A PV (photovoltaic) inverter is the power conversion equipment that converts DC power generated by PV cells into isolated AC power and interconnects it to a utility line. This paper describes a PV inverter with a novel cycloconverter for interconnection to a utility line. The authors developed this novel cycloconverter as a way of frequency conversion so that a small, high-frequency transformer can be used to minimize the size of the PV inverter. They manufactured a 3 kW PV inverter as an experimental model with this novel cycloconverter for interconnection to a utility line. This equipment is 25% the size in volume and 17% the weight compared to previous commercial-frequency isolation type inverters. In rated operations, excellent results were obtained; the output current distortion factor was less than 5.0% and conversion efficiency was as high as 92.1%.