Research On Position Sensorless Control Technology Of PMSM Based On A Novel Sliding Mode Observer With Parameter Adaptation

Permanent magnet synchronous motors have been widely used to its reliable operation.In order to accurately control them,position sensors need to be installed,which increases the system cost and limit the application of the drive in harsh enviroments.Taking the surface-mounted permanent magnet synchronous motor(SPMSM)as the research object,and the position sensorless control strategy of SPMSM based on sliding mode observer(SMO)is studied.On this basis,a novel SMO is built to reduce the chattering phenomenon and improve the robustness of the system to internal and external parameter changes.In the traditional SMO,the sign(-)function is adopted as the control function.In order to reduce the chatteting phenomenon,the low-pass filter and phase compensation are required,but it will decrease accuracy and increase the complexity of the system.Aiming at this problem,the sigmoid(-)function with variable boundary layer width is adopted as the control function,and a back electromotive force observer is adopted.Through this way,not only is rotor angle compensation no longer needed,but also the accuracy of the observer is improved.The stator resistance adaptive strategy is adopted,and the load torque observer is constructed,and the stability of the system is proved by the Lyapunov function,which improves the robustness of the system to the parameter changes.The principle of the hybrid terminal sliding mode observer is analyzed.The non-singular terminal sliding mode(NTSM)manifold is adpopted to realize both fast convergence and better tracking precision,the high-order sliding-mode control law(HOSM)ensures the stability of the system and reduces the chattering phenomenon of the system.In the traditional exponential approach law,an improved exponential approach law is analyzed,which improves the convergence speed of the system while ensuring the accuracy of observation.In order to verify the effectiveness of the proposed method,a simulation model of sensorless control of PMSM by MATLAB/Simulink has been built.The experimental platform of two level inverters with the core of XE164 CPU has also been built up.Simulation and experimental results verify the effectiveness of the proposed control strategy.