Research On Fault Tolerant Control Of Permanent Magnet Synchronous Motor Sensor

Permanent magnet synchronous motor(PMSM)has been widely used in daily life and industrial economy and other main fields because of its simple structure and high power density,and the research of related control technology has been gradually paid attention to.Among them,in the traditional control method,the mechanical sensor placed on the rotor aims to obtain the rotor position and speed,but at the same time,it is easy to be damaged in high temperature,humidity and other harsh environment,which affects the reliability and safety of the system,and even causes the loss of life and property.Therefore,in order to ensure that the system can still operate reliably and stably when the sensor fails,this paper uses sensorless control technology to realize the fault-tolerant control of PMSM when the sensor fails.To solve this problem,the main work of this paper is as follows:Firstly,in view of the failure of permanent magnet motor and sensor,the current situation of research on them is expounded,and the mathematical model of permanent magnet synchronous motor is built in different coordinate system,after analyzing all kinds of vector control algorithms,i_d=0 control strategy is adopted in this paper,which provides a theoretical basis for sensorless control of permanent magnet motor.Secondly,the traditional sliding mode observer is improved according to the characteristics of the motor running at medium and high speed.By introducing the basic principle of the traditional sliding mode observer,the corresponding improvement scheme is proposed for the buffeting.In order to estimate the motor speed and rotor position accurately,the traditional and the improved sliding mode observer models are built by adding Kalman filter and phase-locked loop(PLL),and the simulation results are analyzed.Then,by introducing the principle of high frequency voltage signal injection method,the salient pole effect and high frequency voltage signal injection are used to control the motor precisely.The simulation model of this method is built in Matlab/Simulink to verify the effectiveness of this method in low-speed operation of motor.Finally,the weighted hysteresis switching algorithm is used to realize the combination of the above two sensorless control methods when the motor is switched between high and low speed,and the smooth switching is carried out to realize the accurate control of PMSM in the full speed range.The corresponding model is built for simulation and analysis,which verifies that the proposed improved sliding mode observer method and high frequency injection method can realize the accurate estimation of motor speed,and reduce the error between the estimated speed and the actual speed,reduce the system jitter problem,and can realize the accurate tracking of the motor rotor position,and can achieve a smooth transition in the speed switching.