| At present, energy and environmental problems become increasingly severe, as a new tool for traffic the electric vehicle travel has been sustained worldwide attention. Compared with Germany, the United States and Japan, Chinese electric vehicle technology is still backward, so we urgently need big development. As the core technology in electric vehicle drive system motor control technology must have a strong reliability guarantee, any failure of any link may cause a safety accident, which will obviously obstruct the promotion and marketing of electric vehicles. Fault tolerant control technology can solve the problems abovementioned, so the application of fault tolerant control technology which applied in electric vehicle drive system has important practical significance.It is necessary to improve the reliability and comfort of electric vehicle drive system, due to the fault of the speed sensor caused by the terrible working environment. The accuracy and timeliness of fault detection, the precision of speed estimation, and the stability and smooth of handover algorithm are all important issues. The research is conducted mainly from these aspects abovementioned.Firstly, the development status and trends of electric vehicles are introduced, including the electric vehicle drive technology, the fault diagnosis method, the speed estimation strategy. Secondly, the vector control of induction motor of electric vehicle is studied. And the principle and implementation method are introduced in detail. Thirdly, the speed identification algorithm based on the model reference adaptive algorithm is studied. The existing speed identification algorithm based on model reference adaptive is compared and analyzed. A new speed identification algorithm is studied in this research, the derivation process is analyzed, and the speed estimation performance and parameter sensitivity of the algorithm are studied. Then, the principle of the speed sensor and the common fault form are introduced briefly, and a effective method of fault detection is studied in this paper. The control method of smooth switching before and after failure is mainly studied, and the smooth switching module is designed by using fuzzy control theory. Finally, through the simulation analysis and experimental verification, the feasibility and correctness of the theoretical analysis are proved. |
