Reliability Study Of The Metro Traction Power Supply System Based On Go Methodology

With the rapid development of national economy and the urbanization, as a kind of public transport to ease the traffic pressure, the metro plays more and more important role in urban development and the people’s daily life. The subway power supply system offers the electricity to the metro traffic system, if power supply breaks, not only the whole operating routes interrupts, but also endangers the life safety of the passengers and causes economical loss. Therefore, with the increase of demand for the metro in the domestic major cities, the reliability study of the metro traction power supply system is becoming more important in recent years.First of all, a reliability assessment method, called the GO methodology, is applied into the field of the metro traction power supply system reliability assessment. This thesis takes the metro traction power supply system as a repairable system, introduces the basic principle of the GO methodology in complex repairable system with shared signals, and defines the concept of component fault importance which is applied to component completely independent system. The thesis combines with GO methodology principle of the repairable system, analyzes the reliability of main electrical connection in traction substation, contact networks system, a traction feeding area in one line and medium voltage network. Among them, when the main electrical connection of traction substation is been analyzing, this thesis selects two kinds of the typical main electrical connections, separately carries on the analytic comparison of component completely independent and existing shutdown correlation. At the same time, GO methodology is validated and compared based on fault tree analysis method, and its advantages are given. For the components probability uncertainty, the fuzzy theory is introduced to the GO methodology, six kinds of L-R type fuzzy operator formulas are given which are used to two state systems. And the reliability of main electrical connection in the subway traction substation is analyzed based on fuzzy GO methodology of successful state probability algorithms. This method shows that the calculation results can more accurately to reflect the reliability level of the system, and also is more identical with engineering practice.Second, according to the structure, function and relative independence of the metro power supply system, this thesis divides the general reliability evaluation—RAMS evaluation into nine levels, and briefly reviews the evaluation content of all levels.Finally, the improved group analytic hierarchy process is adoped to allocate the reliability of the metro power supply system. The judgment matrices of group analytic hierarchy process are constructed by the L-R type fuzzy number in this thesis. The improved reliability allocation method considers many factors, such as complexity, important degree, technical level, repair factors, working environment, cost and expense, and so on, which influence reliability allocation, as well as considers the uncertainty of the proportion when the experts are comparing two elements in the judgment matrices. And this method is used to allocate the reliability of the contact networks system. The reliability allocation results are basically identical with engineering practice, which shows that this method is effective and practical.