Study Of The Detection And Protection Of DC Traction Supply System

With the development of economy of china, the question of urban traffic jam had been a more and more serious question; therefore, it would be the only way, which resolves the urban traffic jam, which is developing greatly the city railway, for instance, subways. The subway train is droved by DC traction, and it is strict to stability and security of DC traction supply system. The protection of DC traction supply system is key side of stability and security of DC traction supply system. In this paper, three key technologies of DC traction supply system have been researched, that are the key system parameter detection, the ways of protection and controlling and realization of protection and controlling.It is need to detect the information of the object which is protected timely and stability for the protection system, first. In this paper, detecting the key system parameters has been researched detailed, the feed current is detected by DC measuring instrument, and the feed voltage is measured by the a novel voltage detecting instrument, then these information has been transferred to the CPU, then, the other parameters are measured by software, for example, the current variety, the current increment and times. On the base, the protection principium of DC traction supply system has been researched detailed, and the protection strategy, which are protection in feed current variety and increment detection, protection in current and voltage and times detection, and protection in feed impedance detection, have been set down. After the fault signal of DC traction supply system had been output, the signal of OFF would be output at once by controlling ways, and the ways are flow of ON/OFF output virtually, and they are the other side of protection. The controlling ways had been researched detailed also. Finally, with the researching of protection strategy and controlling ways, the system software and controlling flow had been come true.