A high power active filter for harmonic compensation in an electric locomotive

A single-phase active filter designed for mitigating harmonics output from a locomotive rectifier load in a 25 kV AC network are presented. The proposed active filter is connected directly to the secondary of the locomotive transformer, so that it is most effective in adapting to the varying load conditions. A GTO based voltage source inverter is adopted. The technical problems introduced from high power applications of active filters are discussed. The paper is devoted also in the design of an active filter circuit, the adaptive hysteresis current controller and the performance discussions of the designed active filter. Simulation results using Matlab Power System Blockset verified the concepts and the methods adopted in the design.