Mutiple-Model Based Fault Detection And Isolation For Electric Traction System Of Railway High-Speed

With the rapid development of high speed railways all over the world, China has step into the brand new era of railways high-speed since the sixth national railway speedup. China Railway High-speed(CRH), also known as the ‘Harmony' EMU train, has contributed the world's longest high-speed rail network along with daily ridership of over 1 million, making the Chinese high-speed rail network the uppermost utilized in the world. The efficiency, safety and reliability of railways high-speed, therefore, is prerequisite to achieve a higher degree of train movement and ride quality.This paper is concerned with the design of a multiple-model based fault diagnosis scheme for electric traction system of railways in order to accomplish the task of detecting and isolating multiple faults.Also estimation fusion of asynchronous sensors is introduced to FDI scheme design for improvement.The innovations and contributions are summarized as follows:The model of converter and inverter of the electric traction system of railways is set according to the working principles analyzing,and then improved according to the vector control of induction motor as the load of inverter. The electrical model of induction motor is introduced according to existing researches, and then simplified for the sake of expression and simulation. Some common and easily occurred faults are illustrated in details including their types,reasons,influences and etc.The model set with models of fault and no-fault is established due to the discuss above. Based on the multiple-model methods, a fault diagnosis scheme for induction motor in order to accomplish the task of detecting and isolating multiple faults is proposed by means of designing matching observers so that oriental residuals could be obtained. Simulation results illustrate the feasibility and effectiveness of the designed method as well as the robustness of disturbance and modeling uncertainty of the induction motor system.Further, another fault detecting and isolating scheme based on interacting multiple-model is proposed in terms of some disadvantages from the first method discussed above. Meanwhile,asynchronous sensors multi-rate sensors are taken into account as a fact of railways system, therefore,estimation fusion is introduced to improve the designed estimator. In simulations, multiple component faults such as faults of transistors locating at the inverter are discussed to make the simulation cases more persuasive.Simulation results also demonstrated the feasibility and effectiveness of the designed method.