Study Of Position-Sensorless Control For A Fault-Tolerant Permanent Magnet Rim-Driven Motor Based On Slidinp Mode Observer

As a new type of electric propulsion system developed in recent years,the Rim-Driven Thruster(RDT)integrates propeller blade and motor.It has the advantages of simple structure,convenient maintenance,high power density,good cooling effect,and thus used widely.With the development of technology,the requirements for the response speed,control accuracy and safety of the control system increase more than before.It means that the electric control system that meets the development trend must have good fault tolerance.Therefore,the innovative research direction of Fault-Tolerant Permanent Magnet Rim-Driven Motor(FTPM-RDM)is proposed,which combines the fault tolerant permanent magnet motor and its control technology with RDT.Due to the special structure of FTPM-RDM,the sensor that can measure the rotor position accurately is impossible to be installed.The rotor position information is a prerequisite for effective motor control.Therefore,the study of position-sensorless control for the FTPM-RDM has a great significance for the development and application of RDM.In this paper,the position-sensorless control of FTPM-RDM based on sliding mode observer is studied.Firstly,the structural characteristics and mathematical model of double Y displacement 600 FTPM-RDM is introduced.At the same time,the fault-tolerant control strategy and current hysteresis tracking control technology is described.Secondly,based on the principle of sliding mode variable structure,a rotor position estimation algorithm of FTPM-RDM is proposed.In order to improve the accuracy of estimation and prevent parameter changes during motor operation from affecting rotor position estimation,an online parameter identification method is used.Then,the simulation model of FTPM-RDM position-sensorless control system is built,and the simulation is carried out under the condition of normal operation,one-phase open circuit fault and one-phase short circuit fault.The simulation results verify the correctness of the position-sensorless control method.Finally,the hardware circuits and software programs are designed,and an experimental platform for motor position-sensorless control system based on TMS320F28335 is built.Experiments are carried out under the condition of normal operation and one-phase open circuit fault,and the experiment results verify the correctness of the position-sensorless control method.