Analysis and Design of TRAP and LCL Filters for Active Switching Converters

This paper presents two main filters widely used in industry for three phase active converters. The filters are the Trap and the LCL. These filters are primarily used to reduce switching frequency ripple and to meet IEEE 519 THD requirements. The main goal of this paper is to develop the algorithms which give optimized values of the Inductors and Capacitors of Trap and LCL filters. The algorithm also includes the effect of source inductance. Using the algorithm we will design the Trap and LCL filters for a 125kW active converter. Simulation and experimental results reveal the performance of the Trap and LCL filter. This paper also compares the Trap and LCL filter results.