Study On Fault Location Of Urban Metro DC Power Supply System

Currently , the convenience of transportation has become an important criterion to measure the degree of modernization of a city. The subway transportation is a best choice for development of public transportation for many cities because of its advantages such as green, punctuality rate, large capacity and so on. The subway transportation has played a more and more important part in public traffic of cities. The reliability and stability of subway system is determined by the reliability of power system which is the power base of the subway system. According to statistical analysis of the fault records of Shanghai Metro power system, the 1500V DC level of failure is relatively high, and has lead to significant operational incidents. The security of DC traction system is the theoretical basis of the design and study of the whole urban power system. Once there is a fault occurred on the DC traction power supply system failure, the most important point is the fast and accurate location of the fault.This paper first describes the basic situation of metro power system and analyzes the characteristics of its power supply model, and then calculates step by step using the area location and precise location method. By analyzing and calculation of the model , this paper determines the fault location.This paper presents a promoted Binary Particle Swarm Optimization algorithm for fault location in subway power system. Combining cross-operation with retain-operation of the optimal solution, this algorithm is able to overcome the shortcomings of local convergence by the traditional algorithms and accelerate the convergence rate accordingly. Both single supply power system and AC-DC Hybrid power system in subway are included in the simulation. The simulation results indicate that the proposed method is practical in locating faults in subway power system and is of high calculation speed, good convergence and high fault-tolerance.This paper further studies the precise location of the section of faulty catenaries based on regional location. Taking into account the reality of the situation, this paper divides the faulty section into many small units and establishes a model to change the continuous problem in space into a continuous problem on the plane. This paper also considers the influence of drifting row and the leakage current in the model to make the model closer to the actual situation of the subway system. The use of matrix theory to model determines the faulty unit. Finally, verification of the numerical example proves that the algorithm is effective.