Analysis and design of an active power filter for three-phase balanced electrified railway power supply system

Abstract

An active power filter for electrified railway supply system is proposed in this paper, which is applied to compensate the train's negative, reactive and harmonic current simultaneously and to realize a cophase overhead structure. The filter is consisted of two single-phase 4-quadrant converters connected back to back through the DC-link, and is suitable for the system adopting orthogonal transformers. The system's topology, control strategy and the method of parameter calculation are studied in detail. Results of software simulation are present which has verified the validity and feasibility of the proposed system.