Research On Vector Control Of Permanent Magnet Synchronous Motor Based On Speed Sensorless

Permanent magnet synchronous motor(PMSM)is widely used in the high-precision and high-reliability control fields,such as aerospace,robot,CNC machine tool and so on,because of its advantages of small size,simple structure,high efficiency and superior performance.In the traditional control method of permanent magnet synchronous motor,mechanical sensors such as photoelectric encoder are usually used to obtain the speed and position information of the motor,which not only increases the volume of the system,but also improves the cost of the overall cost of the motor.Therefore,the research of sensorless control method of permanent magnet synchronous motor has gradually become the current development trend.Firstly,the mathematical model of permanent magnet synchronous motor is established by means of coordinate transformation and vector control theory.Aiming at chattering and slow response of the traditional sliding mode observer(SMO),an adaptive fuzzy sliding mode observer is proposed.The method is suitable for middle and high speed operation.Different from the traditional sliding mode observer,the S type function is adopted,and the fuzzy controller is combined on the basis of the sliding mode observer.The fuzzy controller can adjust the sliding mode gain of the sliding mode controller in real time.At the same time,the inverse EMF observer is used to replace the traditional low pass filter.The effect of the system has avoided the generation of the system phase delay.Then the simulation is carried out according to the method and compared with the other two control methods.The surface permanent magnet synchronous motor(PMSM)is not easy to be detected precisely because of its low reverse EMF at low speed.Therefore,the estimation error is relatively large,so the adaptive fuzzy sliding mode observer is not suitable for the low speed operation stage.However,the pulse vibration high-frequency injection method is contrary to it,and its estimation error at low speed is small and the error will become larger with the increase of speed,so this method is selected in this paper when the motor is running at low speed.At present,all of the proposed control methods are applicable only to one of the low speed or middle speed conditions,and there is no single control method that can accurately estimate the rotor information of the motor in the whole speed range.In order to satisfy the condition that the motor runs steadily in the full speed range,this paper adopts the compound control method,according to the advantages of the two control methods in a certain speed range,select the appropriate speed switching interval and the switching method to make the smooth handoff.According to their estimated error difference,the weighted algorithm is used to select the final result.The results of the estimation.On the basis of theoretical research,simulation analysis is carried out by MATLAB/Simulink software,and the results show the feasibility of the method.Finally,on the basis of the software simulation,the experimental platform is built around the Xlinx7010 main control chip,and the soft and hardware design of the sensorless control of permanent magnet synchronous motor is introduced.