Analysis On The Operation And Standby Modes Of Co-Phase Power Supply Device Of The Traction Substation

With the development of heavy burden and high speed electric railway, the power quality problems of the electric railway have been increasingly prominent. The two important issues are the neutral section and negative sequence. Frequently passing neutral section process not only affects the safe operation of train but also severely restricts the train speed and traction. For these two problems, co-phase power supply system is proposed. The neutral section will be cancelled and the power quality problems of electric railway will be effectively improved through compensating negative sequence, harmonic and reactive power by co-phase power supply system. Recently, the investment of co-phase power supply system is greatly reduced through combined co-phase power supply technology. Combined co-phase power supply system will become the new idea of the heavy burden and high speed electric railway development.Firstly combined co-phase power supply system was analyzed to demonstrate the advantages and prospects in this paper. The design method of the traction substation capacity of combined co-phase power supply system was described, and the compensation theory of its key device was studied. Secondly, the reliability of combined co-phase power supply device of different standby modes was analyzed based on the k/n(G) model. The relationship between standby devices and reliability of combined co-phase power supply system was studied. Thirdly, the basic operation modes of combined co-phase power supply device were introduced and the operation modes of combined co-phase power supply system of 1/2 standby traction substation were analyzed. The influence of co-phase power supply device operation modes on temperature rise and the loss of life of traction transformer was analyzed through the transformer temperature rise model with actual load. The influence of co-phase power supply device operation modes on the neutral voltage of co-phase power supply system was studied through the inequilateral SCOTT transformer neutral voltage model with actual load.In the end of this paper, the design method of the traction substation capacity of combined co-phase power supply system was made based on the properties of traction load. The optimization on the operation modes and standby modes of co-phase power supply device was made based on the conclusion of this paper to reduce the investment of combined co-phase power supply system.