Study On Feeder Protection And Fault Location Of All-Parallel AT Traction System

At the economy highly developed today, railway is going toward high speed, heavy duty. Building the High Speed Railway (HSR) or passenger-transport special line is to meet the development of our economy and the demand of the state of the nation. HSR will adopt electric traction necessarily. The power supply system is the most important part of electrified railway, so its power supply mode also becomes one of the key factors that develop the HSR. AT feeding systems with the advantage of itself, got the extensive application in France, Japan, also be paid more and more attention by our railroad.The experiences from regular speed railway indicates that the fault ratios of power supply networks in China are higher than other countries and wrong operation of protective devices often occurs in Chinese power supply systems by reason of the technical and management levels. The foreign advanced techniques can certainly be adopted to service Chinese railway transport, especially HSR transport. According to the characteristics of all-parallel autotransformer (AT) power supply system, systematically studied the protective principles of feeder and fault location and put forward novel protection and fault location for HSR.Based on the equivalent circuit of the AT power supply system, the equivalent circuit of AT power supply system with protection wire is proposed. With this equivalent circuit, the impedance of feeder can be easily calculated, so the theoretical basis is offered to the protection setting. Then the simulation model is built to analyze the impedance of various faults and the results of simulations indicate the correctness of the calculated impedance with the equivalent circuit.According to the characteristics of all-parallel AT power supply system, put forward an applicable protection scheme, and then put forward an applicable protection flow and the configurations of the protection, finally detailed analyze protections of various faults.Based on the protection scheme, put forward a newly and easily method to locate the fault location. The new method is different from others. It can calculate the fault distance only using the local data and can be easily carried out.