Research On Speed Sensorless Control Of Synchronous Reluctance Motor Based On ADRC

Synchronous Reluctance Motor(SynRM)is widely used in air compressors,fans,electric vehicles and other fields because of its wide speed range,strong overload capacity,low cost,high reliability and insensitive temperature rise during operation.In order to ensure the control accuracy of position and speed,it is often necessary to install a position sensor to measure the position and speed of the rotor,which makes the motor occupy a large volume,cost is high,reliability is low,and immunity is weak.Therefore,this paper takes synchronous reluctance motor as the research object,and studies its speed sensorless control strategy and the control strategy to enhance system immunity.A speed sensor-free control strategy based on a magnetic chain observer is studied to solve the problem that the speed sensor can reduce the reliability and increase the cost of the system when SynRM implements high-performance control.However,the cross-coupling effect exists during the operation of SynRM,which causes the inductance to change nonlinearly with the current,which reduces the accuracy of the rotor position estimated by the flux observer.To reduce the cross-coupling effect of SynRM,voltage with different amplitudes and frequencies was injected into d-q axis by static experiment.Forward Euler method was used to calculate d-q axis magnetic chain.Linear least squares method was used to fit the non-linear function model of d-q axis magnetic chain and current.Finally,the function model was applied to the magnetic chain observer to improve the accuracy of estimating the rotor speed and position.To overcome the drawbacks of weak immunity and low robustness when SynRM uses a magnetic chain observer,a speed sensorless controller strategy for SynRM based on auto-disturbance rejection technology is studied.Firstly,the design principle of the ADRC is analyzed and an ADRC suitable for SynRM is selected.According to the SynRM mechanical motion state equation,the variation of load is considered as a total disturbance,and the disturbance is quickly observed and compensated.In view of the disadvantage of large number of parameters and complex adjustment in ADRC,linear function is used instead of original non-linear function to reduce the number of adjustable parameters,reduce me adjustment complexity and select appropriate parameters of ADRC.It improves the robustness and robustness of the system.Finally,a MATLAB/Simulink simulation model of speed sensorless control strategy for synchronous reluctance motor based on auto-disturbance rejection technology is built to verify the validity of the above methods,and the proposed control method is verified by an experimental platform.The results show that the proposed scheme can effectively reduce the cross-coupling effect of SynRM,improve the accuracy of rotor position estimation,and enhance the system anti-disturbance performance.