Phase Shifting Transformer-LCL (PST-LCL) Filter: Modeling and Analysis

摘要

Power converters have been widely used in power systems to improve 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 reduce the harmonics generated by the inverter. Based on the different design methodologies, optimal parameters of LCL filters tend to differ in wide ranges. This paper proposes a new approach to an LCL filter used for decreasing the harmonic currents. A phase shifting transformer is added into the structure of an LCL filter to mitigate the harmonic current. The procedures and techniques described in this paper are particularly suitable for the grid-connected photovoltaic energy systems.