State Degradation Assessment For High-Speedrailway Catenary

With the rapid development of China’s high-speed railway, The importance of Catenary System is self-evident. In order to ensure safe and stable power supply, It requires us to be able to assess the catenary current degraded state,analysis the trend of the state degradation,its state of degradation research will not only improve the stability of power supply, but also optimizing maintenance costs and maintenance plans, as a condition maintenance basis.Firstly, analyzed the structure of catenary and catenary fault with the state degradation, should make an overall assessment of the state of degradation of the catenary system; Analyze shortcomings of the traditional use of a single parameter to evaluate the amount of ways, propose the use of multi-parameter integration to determine the degradation state of the catenary, choosing the fuzzy comprehensive evaluation method and Hidden Markov model to to assess the catenary degraded state.Established the three-tier hierarchy system for index based on the principle. discussed the modeling of fuzzy comprehensive evaluation method in high-speed rail catenary state degradation assessment; Analyzes the conventional weight calculation method-AHP, For the shortcomings of AHP entirely dependent on the subjective views of experts, using of Balance Function to objective improvemnet; combined with high-speed rail catenary operating characteristics select of Normal Distribution membership function to calculate the evaluation matrix, avoid the expert scoring no basis and subjective; combined with the measured data to application research, and to compare with using Often Right calculation. Proved the Variable Weight Improved assessment results a more reasonable.Discussed the modeling principle of discrete Hidden Markov model, focuses on the process by use Hidden Markov Model to assess Catenary state degradation. Using the communication encoding field quantiz algorithm for data scalar quantization before HMM model training. Using the measured data of a line in South Guangzhou-Qingyuan to application, according to the modeling steps, the program of state identification is developed in Matlab environment. The comparison of recognition is carried out under different quantization precision. Finally, the quantitative analysis of the performance degradation of the catenary is carried out. The performance degradation index (PDV) curve is drawn, it met the performance degradation trend of the catenary.