A New Approach to LCL Filter Design for Grid-Connected PV Sources

Abstract

Power converters have been widely employed in power systems to enhance the quality and magnitude of the power drawn from renewable energy sources. An LCL filter for connection of an inverter to the grid is often used to mitigate the harmonics generated by the inverter. Based on different design methodologies, optimal parameters of LCL filters tend to vary in wide ranges. This paper describes a new approach to an LCL filter used for minimizing the harmonic currents. A phase shifting transformer is inserted into the structure of an LCL filter to minimize the harmonic current. The procedures and techniques described in this paper are particularly suited for the grid-connected photovoltaic energy systems.