Rotor Position Detection And Vector Control Of Sensorless SPMSM In Full Speed Range

Permanent magnet synchronous motor is widely used in industrial control system with the advantages of high efficiency,small size and so forth.According to the characteristics of surface mounted permanent magnet synchronous motor(SPMSM),this paper analyzes the application of non-sensor technology to replace the position detection device from the point of view of practical application.Through analysis of a large number of relevant literature and on the basis of summarizing the results of previous studies,we study the SPMSM sensorless vector control technology mainly from the torque ripple,low speed performance,high speed performance,the initial rotor position detection,the rotor speed and position dynamic tracking and other aspects on the basis of summarizing the results of previous studies.On the basis of deep research on sensorless rotor position detection and vector control technology of permanent magnet synchronous motor,the sensorless vector control system is established and the simulation analysis is carried out.First,SPMSM is selected as the basic research object,theoretical analysis on the mathematical model of the motor body is conducted,the conversion of voltage and current in different coordinate systems are studied.Based on that,the mathematical models of SPMSM in different coordinatesystems are established,and the SPMSM speed and current double closed loop control system isestablished to verify the simulation results.Secondly,research on SPMSM sensorless control technology in low speed condition is conducted.The method based on high frequency voltage injection was adopted to solve address the problems of the fundamental wave model in the low speed.In this paper,a method of high frequency voltage signal inject in the direct-axis((9-axis)and detect the magnetic pole's position of the quadrature-axis(-axis)is selected to process the extracted high-frequency current signal of the q-axis.Thus,the signal of rotor position observer is obtained after the filter,so that the position of the rotor can be identified when the magnetic pole's position is detected at low speed.The principle of flux paths saturation salient effect is adopted to solve the starting failure problem of PMSM at zero speed.On the basis of getting rotor position at the beginning,input voltage pulse of same width from positive and negative direction in (9-axis.By observing the saturation degree of flux paths and the amplitude of d-axis,the positive direction of the d-axis is judged,and the initial position of the SPMSM is accurately located.The high frequency current component is extracted from the stator current by a high pass filter,as the input signal of the rotor position tracker,the high pass filter in the synchronous reference axis coordinate system is designed in the extraction of the fundamental current,the positive and negative sequence components were filtered in the high frequency component of stator current,extract the fundamental component and feed it back to current regulator for the current closed loop control.Then a study for common speed sensorless control method which is suitable for medium and high speed has been made,focused on the sliding mode variable structure control(SMC)method and the auto disturbance rejection control(ADRC)method.In the first place,in view of the deficiency of the sliding mode variable structure,transform the original switching function into hyperbolic tangent function(tanh),the phase locked loop with normalized processing is added at the same time.The fal function is applied before the control object in the ADRC control system.By introducing the concept of time scale,the parameters of ADRC are calculated directly after calculating the time scale of the control object.Next,Based on the above analysis,two kinds of methods which are suitable for medium and high speed are combined together,and the sliding mode variable structure control is introduced into the design of the speed and current active disturbance rejection controller.By using the method of sliding mode variable structure reaching law to improve the ESO and NLSEF nonlinear characteristic function control parameters.For the improved nonlinear extended state observer and the improved nonlinear state error feedback control law,use continuous relay characteristic function ()to replace discontinuous switch sign function 4)2)9)(?)and make a controlled variable continuous,so that the actual high order ESO and NLSEF control parameters are reduced,which can be convenient to adjust the parameters of the actual motor speed regulation system.For TD link speed controller,the control method is simplified by using the fastest discrete function,so that the ADRC system can alleviate the contradiction between the dynamic response and the overshoot of the motor.Through the above analysis,the two order SM-ADRC controller of the speed current loop is designed,in addition,through the analysis on the d-axis current output equation,a new current loop one order SM-ADRC controller is also designed.The two controllers are applied to the medium and high speed vector control system in SPMSM at the same time,and finally a medium and high speed control method based on SM-ADRC is proposed,which makes the operation performances of SPMSM in medium and high speed are obviously optimized.Finally,combine the high frequency pulse voltage injection method which is suitable for low speed are combined together,and the speed weighted method is adopted to achieve the two kinds of magnetic pole position detection algorithm of smooth switching;A composite observer for rotor speed and position of SPMSM in full speed range is established,and a sensorless vector control system is established for the SPMSM full speed range.The correctness of the proposed composite observation estimation method is verified by the simulation results.