Reliability Analysis And Evaluation Of Traction Power Supply System For Passenger Dedicated Line

Under the new situation, high-speed dedicated passenger line (DPL) is being quickly changing during a leap in the development stage, which will reach 16,000 km until 2012. Traction power supply system (TPS) is part and parcel of DPL, which can provide electric energy for motor train-sets. So, the reliability of traction power supply system can guarantee DPL's safe operation and steady transportation and provide DPL with accurate theoretical foundation that is necessary to make operating decisions and maintenance strategies, which is directly related to railway transportation dependability and safety. Due to the importance of traction power supply system reliability research, this paper concentrates on structure and elements, maintenance,relay and software development of TPS, in order to find the quantitative relationship between maintenance,relay and TPS, to improve TPS reliability, to serve DPL better.Significance and situation of TPS reliability research has been stated. From existing references two important points of penetration—TPS reliability analysis considering maintenance and relay.In allusion to structural features of TPS,3F(namely synthesis of Failure Modes and Effects Ananlysis(FMEA),Fault Tree Ananlysis(FTA),Failure Reporting, Analysis & Corrective Action System (FRACAS) )technique has been introduced for analyzing TPS reliability, FMEA tables, FT models,FRACAS of TPS have been created,synthesis application of 3TPSF has been conducted.3TPSF technique is an organic combination that have interaction with each other, which can make cause and effect of failure events clear, accumulate system reliability data, and effectively prevent similar events from reappearing. Thus, it is a practical way to TPS reliability research.Maintenance is one of important factors which can affect TPS reliability. To illustrate the quantitative influence that maintenance produces on TPS reliability, traction substation main connection was chosen as object of study. Firstly, theoretical analysis process,features and results of basic series and parallel reliability system are stated in detail. And then, based on analysis of the basic series and parallel reliability system, irreparable reliability models and reparable reliability models of traction substation main connection have been established, the ways of how to get mean time to failure (MTTF) and mean time to first failure (MTTFF) of two models are achieved. Subsequently, by comparative analysis of the value of MTTF and MTTFF of traction substation main connection reparable and irreparable models, and comparative analysis of the value of MTTF and MTTFF among three kinds of traction substation main connection reparable and irreparable models.Lastly,the following conclusions are found:the values of repairable model's MTTFF is undoubtedly larger than its MTTF,the values of reparable model's MTTFF is undoubtedly larger than that of irreparable model's MTTFF, the comparison of the values of reparable model's MTTF and irreparable model's MTTF depends on the value of component maintenance rate, the value main connection reparable model MTTF and MTTFF model is not surely greater than that main connection reparable model. These conclusions gave useful guidances for TPS reliability planning,design and establishing of maintenance strategy and standard.Protective relay is the first defense line of TPS safe and dependable operation. However, high-speed DPL protective relay has adopted digital technologies with multifunction. To illustrate the influence that digital protection produces on TPS reliability, based on function of digital protection, a new reliability model is proposed that associates protection system failures to four main causes:1) relay hardware,2) relay software,3) ancillary equipment, and 4) human error. In addition, this model can take other aspects of the protection system into consideration, such as human error during tests and repair actions, routine inspections effectiveness, level of reliance on self-checking, local backup misoperation, and stuck breakers. These considerations have a significant impact on the reliability of protection systems and some of that have been neglected in the existing research works. Various capabilities of the model such as how relay hardware and software failures, self-checking and routine inspections interval affect reliability of TPS components and protective system, how to get the best self-checking and routine inspections interval are demonstrated in the case study section.This model can be used to check relationship between lots of questions and system reliabilityTo analyzing TPS reliability more conveniently and quickly, based on FMEA and FTA that have been applied popularly in existing research works, "TPL TPS reliability evaluation and data management software " has been developed, which can help FTA modeling, FMEA table creating and effective relevant reliability data managing.