Some Key Problems on Cophase Traction Power Supply Device

This paper analyzed a scheme of cophase traction power supply system for electrified railways based on cophase traction power supply device (CTPSD). The advantages of this new CTPSD over other controllers are presented by describing the main circle, functions and control strategy in detail. Furthermore, the two typical behaviors which are normal running and regenerative barking of the electrical locomotive are simulated to present the balanced conversion and compensation effectiveness. Results shows that the cophase traction power supply system based on CTPSD is a good solution for the seriously-unbalanced three phases, reactive power, low power factor and harmonic current existing in traction power systems for electrified railway. Combined with the energy storage system, CTPSD can further solve the problem of electrical locomotives´ regenerative braking power-feedback.