The Grounding Protection Way Of Single Core Cable In High Speed Railway Traction Power Supply System

With the rapid development of economy and railway industry, single core cable is more and more widely used in railway, it also brings some problems. In the high-speed railway, the feeder cable connection between the traction substations and the traction network, bear the responsibility for the transmission of electrical energy. If the feeder cable fault will cause the entire traction arm lost electricity, so the feeder cables are important in the status of traction power supply system. This paper first analyzes the research status at home and abroad for the feeder cables, in view of the domestic and foreign less research in laying way and lightning overvoltage, this article will carry on the key research.In combination with the practical situation of high-speed railway, this paper used PSCAD/EMTDC simulation software set up the feeder cable and the High-speed Railway All-paralle AT Traction Power Supply System model. Through the simulation model analyzes the influence of core voltage, core current, the length, grounding mode, and grounding resistance. The results show that the sheath induced voltage with the core current, core voltage and the cable length increase linearly increased, the core voltage less effect on the sheath induced voltage.In order to analysis suitable laying mode and laying spacing for railway cable, this paper let reduce the cable Sheath induced voltage and cutting down the cost of the project as a starting point for simulation analysis. The result shows that T line cable and F line cable laying together can reduce the cable Sheath induced voltage and cutting down the cost of the projects than T line cable and F line cable laying Separately; when T line cable and F line cable laying together, the TFTF cross parallel laying, TFTFT cross parallel laying and TFTFTF cross parallel laying mode can reduce the cable Sheath induced voltage and cutting down the cost of the projects than the common used TFTF parallel laying, TFTFT parallel laying and TFTFTF parallel laying mode. In the case of two cable lying together, When the core current phase difference of 0°-110°, Its induced voltage mutually reinforces; When the core current phase difference of 120°-180°, its induced voltage mutually weakens.Finally studied the influence of lightning strike location, lightning arrester, cable sheath protector, and number of parallel cable. The simulation results show that when lightning strikes within 100m of the line connected to the cable, it will produce very big impact lightning overvoltage on cable core and sheath, this time will be required to have lightning arrester and cable sheath protector to lower cable core and cable sheath lightning overvoltage, As well as increasing the number of cable in parallel to reduce cable core current and sheath voltage, to improve the level of the insulation of the cable and power supply reliability.