Research On Speed Sensorless Control System Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in AC drive and servo control because of its advantages such as simple structure,high efficiency and small volume.It is the key that to realize the control strategy of PMSM is to get the rotor position and speed information of the motor.The above information can be measured by mounting sensors on the rotor,however,this strategy would increase the cost of electrode manufacturing and the size of the motor,in addition,it has limitations in some special environments.In this paper,the speed sensorless control of permanent magnet synchronous motor is studied as follows:Firstly,the background and development status ofPMSM direct torque sensorless control and electric vehicles are described,Different mathematical models were established in different coordinate systems,and the basic principle of direct torque control was illustrated by simulation,which can be seen that the torque pulsation was larger.In this paper,zero vector modified switch table was used to reduce pulsation when load or speed change,which improved the stability of the control system.Secondly,model reference adaptive algorithm(MRAS)was used to estimate the speed in real time instead of the sensor.The algorithm of resistance identification was added to form a two-parameter algorithm for detecting resistance and speed at the same time,considering that resistance will change with temperature change.After identifying the resistance,the numerical value was substituted into the current identification algorithm through simulation verification that the required speed can be estimated effectively,that resulted in the improvement of control accuracy and the reduce of calculation error.Finally,a fractional synovial regulator was designed to replace the traditional PI regulator to weaken the PI speed regulator caused by the problem,which was aiming at the traditional PI regulator was not robust enough to meet the problems of rapidity and stability.The simulation results showed that the proposed algorithm can effectively improve the robustness and stability.Figure[40]Table[5]Reference[68]...