Investigation Of Position Sensorless Control System Of Fault-tolerant Permanent Magnet Motor Drive Based On Back-EMF Method

In some areas, such as medication, aerospace, nuclear industry and so on, electrical transmission systems are directly related to the safety performance of the entire control system. Therefore, the study about fault tolerant permanent motor and its control strategies have greater significance and far-reaching impact to development of the areas. In order to implement precise control to fault-tolerant permanent motor, the rotor position and speed of the motor have become an indispensable condition. Presently, this information is conveniently obtained through a mechanical position sensor. The use of mechanical position sensors can easily get the rotor position and speed, but it brings some problems to entire control system. Therefore, position sensorless control technology has gradually become a hot topic in the field of the motor control.The paper mainly researches the position sensorless control technology of the fault-tolerant permanent magnet motor. Firstly, the paper introduces the basic structure and features of three-phase fault-tolerance permanent magnet motor, the control strategy of hysteresis current tracking, one-phase open-loop and one-phase short-circuit and so on. Secondly, the paper basically introduces about the mathematical model of the three-phase fault-tolerant permanent magnet motor. The paper researches two improved algorithms that apply to the fault-tolerant permanent magnet motor. This paper introduces a speed observer so that reduces the impact of high-frequency interference on rotor speed. Thirdly, the simulation model about the position sensorless control system of the three-phase fault-tolerant permanent magnet motor based on back-EMF method is built by Matlab/simulink, and the two improved algorithms of the rotor position simulate verification at low-speed, medium-high-speed, one-phase open-loop and one-phase short-circuit operation. Lastly, the position sensorless control system of the three-phase fault-tolerant permanent magnet motor based on the back-EMF method is designed on hardware and software. TMS320F28335 is used for experimental verification of the second rotor position esitimation algorithm which applies to fault-tolerant permanent magnet motor.and analyzes to the results of the experiments.