Research Of Sensor Fault Tolerant Control Of Induction Motor

The vector controlled induction motor drive system is widely used in various industry fields, which control performance can be comparable with DC motor. However, the poor working conditions or disoperation may cause the system components some faults, among them, the sensor is the most vulnerable part. In the vector control system of induction motor,current value and speed value is necessary for the closed loop control. Once the speed sensor faults or current sensor faults, there is some inaccurate feedback information even no feedback information in the control system, which will further affect the control performance of the whole system, and even lead to system collapse, huge economic losses and casualties.Therefore, the fault tolerant control (FTC) for current sensor faults and speed sensor faults is particularly important. In this paper, a more simple fault tolerant control method is proposed for the current sensor faults, a higher reliability fault tolerant control method is proposed for the speed sensor faults.At first, induction motor mathematic model in the two-phase static coordinate is given.Then, a current estimator, two virtual sensors (extended Luenberger observer and an extended Kalman filter), current and speed sensor fault tolerant control methods are described. Finally,the simulation model of sensor fault tolerant control method is established in the MATLAB,and the simulation results show the correctness and effectiveness of the FTC method proposed in this paper.In order to verify the feasibility of the proposed fault tolerant control method in this paper,1.5kW experimental platform which takes TMS320F28335DSP as the core was built, the experimental results show that the system used the proposed approach can make the motor continue to work with good control performance even in the presence of speed sensor faults or current sensor faults.