Research On DC-side Fault Location Of Urban Rail Transit Power Supply System

With the development history of more than100years, urban rail transit has become the lifeblood of many urban transport systems. And how to ensure safety and reliability of urban rail transit DC traction power supply system has become the focus of research. Catenary (the third rail) is an important part of the traction power supply system, the vast majority of urban rail power supply system failure is Catenary (the third rail) grounding fault in practical. Catenary (the third rail) has no alternate line, if a fault occurs, the traction power supply would be interrupted, than the operation quality of urban rail transit would be affected, at last lead to operation losses. Therefore, it is particularly important that the fault position can be quickly located after a Catenary (the third rail) fault occurs.Urban rail transit system has multiple power operating modes, the DC side fault type is great and little of abroad for study of urban rail transit DC side short circuit fault location, so how to locate the DC-side fault is difficult. This paper focuses on how to complete urban rail transit DC-side short-circuit fault location, the main work is completed as follows:(1)Analyze various power supply mode of urban rail transit system, and model and simulate the power supply system by combining with the actual parameters;(2)Research principle of two-terminal impedance method, set up fault location algorithm by combining with the short-circuit characteristics of urban rail transit DC power system, and verify the accuracy of this algorithm by MATLAB simulation;(3)Research principle of the Bergeron model, develop a fault location algorithm based on time-domain Bergeron model, and design the specific operation method combine with the actual situation. Use this method to simulate and analyze short-circuit situation in different resistance and fault position, verify the feasibility of this program;(4) Study the advantages, disadvantages and scope of the impedance method and time domain fault location scheme based on Bergeron model, combine with these two schemes to develop a optimized fault location scheme to locate any type of short circuit fault, and verify the feasibility of this optimized fault location scheme by simulation;(5) For some line parameters are not fully given, propose the fault location method of time domain based on genetic algorithm. List the scope of the inaccurate amount, translate the fault location problem into a multi-objective problem for the minimum. Preparation of the corresponding program and verify the feasibility of this program by simulation.