Research On Fault Analysis And Protection Methods Of DC Traction Power Supply System

With the high-speed development of the national economy and the growing population of city in China.Urban railway become the best choice to alleviate the urban traffic problem. The safety and reliable operation of DC Traction Power Supply System is the foundation. Fault analysis, protection methods research is of great significance for DC Traction Power Supply System.How to detect,remove,isolate and further troubleshooting the fault timely and accurately,maximum ensure the trouble-free range of power supply is the important measures to protect the safety of urban railway.Dc circuit breaker used in the DC Traction Power Supply System has many technical and economic problems,A new type of DC Traction Power Supply System by using ac circuit breaker and dc isllating switch to dispence dc circuit breaker is researched in the paper.Firstly,the paper outlined the composition of DC Traction Power Supply System, theoretically analysised the 24 pulse wave rectifier and the dc side protection method,revealed the difficulty of extinguishing the arc by analysing the characteristics of ac and dc circuit breaker.Secondly, put forward a new kind of dc traction power supply system and protection methods,defined the power flow symbol value for dc bus fault and the voltage symbol value for the contact line fault,designed the protection treatment process for different fault type.Thirdly,established the 24 pulse wave rectifier and verified its accuracy by simulaion,explored the characteristics of dc short-circuit current in two cases,established the model of dc power supply system and its protection system.Fourthly,verified the dc traction power supply protection system by analysing the simulation on different fault types, analalysed the fault location.At last, discussed its partitioning scheme and economy, analalysed the scheme of data acquisition,transmission network.data synchronization scheme and the processing algorithm.