Research On Online Reliability Evaluation For Traction Power Supply System Of Metro Network

With the expansion of domestic urban metro network, the safe andreliable operation of power supply system, whose outage will not onlycause huge economic losses to the society, but also be more likely toendanger the safety of the passengers so as to have extreme negativeimpact on society, has received more and more attention.It is of great importance to guarantee the safe operation of metro byfinding a kind of method, which can be used to evaluate the reliability oftraction power supply system in real-time environment and, furthermore,forecast the reliability of power supply system for the near future so as tohelp operators find failure-sensitive equipment and do the maintenancework with more pertinence.An event-based reliability evaluating solution for traction powersupply system of metro has been put forward on base of the analysis forcharacter, operating method and common outages of traction power supplysystem of metro. Once short-circuit, open-circuit, or overload, which leadsto outage caused by action of protection, takes place on certain equipment,reliability evaluating process will be triggered on and availability andusability of related equipment will be calculated at the same time. Afterthat, power supply pathways will be searched from source to contactnetwork. Once outage is found in contact network, system usability will becalculated. An improved DFS algorithm has been presented whensearching the pathways and at the same time, a zoom-based dynamicmethod, which has been used to simulate the post-failure change ofnetwork by protection and manual switch operation, has been proposed.Secondly, load-based outage rate model and outage probability modelfor equipment have been built on base of existed equipment model forreliability analysis. Moreover, with the help of load forecasting method, ashort-term load forecasting based solution for forecasting reliability level of traction power supply system has been created, which can give thereliable operating probability of traction power supply system in the nearfuture.In order to validate the feasibility and effectiveness of new proposedsolution, a software has been designed and developed on platform ofVS6.0, which can be used to draw the single line diagram of tractionpower supply system, simulate the operating load of trains, receive faultinformation on intranet under the TCP/IP protocol, evaluate and forecastthe reliability of traction power supply system online.At last, the feasibility and effectiveness of new proposed solution hasbeen validated by two simulation examples and give valuable reference topractical application of this new solution.