Research On Current-carrying Characteristics Of Pantograph-catenary System Based On Grey Theory And Fuzzy Evaluation

Since the beginning of the 21 st century,the state has increased its investment in the electrification of railways.Railways have developed rapidly.Electrified railways have become the most important mode of transportation in China.After decades of rapid development,China's high-speed railway has become the world's first.At the same time,as a national business card,it is particularly important to ensure the safe and efficient operation of high-speed railway.The electrified system is an important part of high-speed rail,which affects the operation safety of high-speed rail,and is also the key technology restricting the development of high-speed rail.Therefore,scientific research on the current-carrying status and quality of the electrified system has important practical significance for high-speed rail to operate efficiently and safely.In this thesis,the pantograph-catenary system is studied from the angle of current carrying performance,and the operation of high-speed railway pantograph-catenary is simulated by a test machine.According to the experimental results of current carrying performance,the reasons for the change of current carrying quality are analyzed from three angles: velocity,fluctuating load and current.Three different conclusions are drawn: velocity increases friction force,while the pantograph-catenary contact surface generates debris accumulation;fluctuating load makes pantograph slide resonate when it is impacted;current makes current carrying performance better,but changes wear performance of pantograph-catenary contact surface.According to the hierarchical chart of current carrying quality performance indicators and influencing factors,the evaluation matrix is constructed,and the grey model method is used to calculate the correlation degree between performance indicators and influencing factors,and the shortcomings of the traditional grey model are improved.This thesis uses the method of entropy weight to weigh the importance of each influencing factor to the evaluation index,and uses the dynamic discrimination coefficient to reduce the influence K of factors on the correlation degree.Based on the improved grey correlation model,the calculation of the correlation degree of the experimental results shows that the contact pressure and the contact current are the most important to the correlation degree of the current carrying performance index.Finally,in order to change the traditional single-angle current-carrying performance evaluation method,this thesis uses the fuzzy comprehensive evaluation method to evaluate the current-carrying performance,and incorporates three evaluation indicators(current-carrying rate,current-carrying stability and contact resistance)into the fuzzy function.The fuzzyfunction of current carrying performance is calculated by experimental data,and the current carrying performance is classified.This thesis has 32 copies,13 tables and 59 references.