The Electric Car Motor Drive System Sensor Fault Diagnosis And Fault Tolerance

With the energy crisis and the global environmental problems deteriorating gradually, electrical vehicle (EV) is concerned by a lot of countries, and its safety and reliability become the key points of the experts’research in this field. As the core component part of EV, motor drive system working reliably is the requirement of EV driving normally, and its operating state influences the performance and function of EV. Therefore, it is an effective measure for improving the performance of EV to diagnose and remove the faults in motor drive system quickly and accurately. As sensors in motor drive system with a high probability of faults, it is very important to diagnose and deal with the faults. For current and speed sensors in motor drive system, this paper establishes a system to diagnose the faults and achieve fault-tolerance. The main contents in this paper are listed as follows.1. The structure and the principle of operation of motor drive system are analyzed, and the effect of accurate output of sensors to keep the performance of the system is clarified in this paper. This paper also makes a deep investigation and study on V/F control, vector control and vector control without speed sensor.2. This paper makes research on principle of operation and common faults of speed sensor in motor drive system of EV. After the study of RBF artificial neural network (ANN), this paper establishes a method to make online diagnosis to speed sensor based on RBF ANN, and verifies the effectiveness of this method by simulation.3. The principle of operation and common faults of speed sensor in motor drive system of EV is studied. With the redundant design of current sensors, this paper can make online diagnosis to single phase current sensor, and raises a method to diagnose the multiphase current sensors. The effectiveness of the diagnosis method is proved by simulation. 4. This paper designs a fault-tolerant strategy for sensors in motor drive system of EV, which can choose the optimal control method to control the induction machine according to the situation of the current and speed sensors. In the process of the change between the control methods, this paper smoothes the change process to advance the safety of EV. The result of the simulation of the fault-tolerant system described in this paper illustrates this strategy can make EV works effectively when sensors work abnormally, and the experiments of this strategy on the platform of1.1KW motor indicate that it does raise the reliability and safety of EV.