Research On The Position Sensorless Control Algorithm Of Permanent Magnet Synchronous Electric Drive System At Full Speed Range

With the development of social economy,energy demand is increasing,pollution of the environment is increasing,and sustainable development has become the focus of attention.Under this background,traditional fuel vehicles are being replaced by new energy vehicles.As the dynamic core of new energy vehicles,electric drive system plays a vital role in its performance.Permanent magnet synchronous motors are widely deployed in new energy vehicles due to their advantages in efficiency and power density.The position sensorless control technology not only reduces the control system cost,reduces the hardware complexity,improves the reliability of the drive control system,but also avoids the limitation of the mechanical position sensor on the installation and operation environment,and has gradually become a research hotspot.Influenced by the nonlinearity of the inverter and the spatial harmonics of the magnetic field,the stator current and the back electromotive force of the motor contain relatively obvious harmonics.If they cannot be effectively suppressed,the torque ripple will eventually be caused,which will affect the running performance of the vehicle.Focusing on this issue,the main work of this paper is as follows:1)A non-singular terminal sliding mode observer is designed for the built-in permanent magnet synchronous motor(IPMSM),which realizes the accurate observation of IPMSM back electromotive force,and then provides conditions for position acquisition.2)An adaptive filter based permanent magnet synchronous motor observation position pulsation suppression scheme is designed.In order to analyze the influence of inverter nonlinearity and motor space magnetic field harmonic on the motor back electromotive force and observation position,a back electromotive force filtering scheme based on second-order generalized integrator series is designed to improve the position observation accuracy.3)A comprehensive harmonic suppression strategy based on closed-loop control of back EMF harmonics is studied.The high-order sliding mode observer is used to observe the high effective back EMF of the motor,and the rotating integrator is used to control the 5th and 7th harmonic components of the observed back EMF respectively,which enhances the system's ability to suppress harmonics.The effect of comprehensively suppressing the observation position pulsation,current harmonics and electromagnetic torque pulsation is realized.4)A position sensorless composite control scheme for permanent magnet synchronous motor is designed.The high-frequency pulse injection method and the sliding mode observer method are combined,and the weighting coefficient is designed to realize the smoothing of the two observation schemes.IPMSM full speed range without position sensor control.5)Based on the MATLAB/Simulink simulation model and the laboratory simulation experiment platform,the simulation and experimental verification of the proposed position sensorless control scheme are carried out.