A Evaluation On Reliability Of External Source For Traction Power Supply System

With the development of China electrified railway, especially large-scale construction of high-speed passenger line in recent years, electrified railway reliability issues increasingly became the focus of attention. Traction power supply system is to achieve an important support of the electrified railway traction power supply system, external power through the traction power supply system to transfer the energy and convert it into electric locomotive required standard, external power supply of the traction power supply system reliability level is directly related to normal driving of the electric locomotive, so an external power supply of the traction power supply system reliability evaluation is necessary.The main purpose of an external power supply of the traction power supply system reliability evaluation is consider the uncertainties related to external power supply of traction power supply system, and gives comprehensive consideration in terms of likelihood and severity, and ultimately gets the corresponding reliability evaluation index. At present, the reliability index calculation method is divided into two types of analytical method and simulation method, due to the exponential growth in the amount of analytic methods with the increase of system elements, the analytical method is mainly applied to system reliability evaluation which elements is less; relative to the analytical method, the calculation of the simulation method is not affected by the size of the system, but the simulation calculated is low efficiency, high dimensional and static defects, and can not take into account the linkages between the various components of the external power supply traction power supply system.For the problems of traditional reliability evaluation methods, introduced the Markov chain into Monte Carlo simulation, and establish a reliable external power supply of traction power supply system assessment model based on Markov chain Monte Carlo simulation (MCMC method), using Matlab simulation platform design a reliability evaluation software based on the MCMC method, and applied it to evaluate the reliability of a traction power supply system on the basis of IEEE-RTS79. The results verified the correctness of reliability evaluation method which based on MCMC. Compared with the traditional Monte Carlo simulation,the MCMC method improve the convergence rate and have a strong advantage on computation time, and improve the stability of the reliability evaluation.