Research On Suppression Strategy Of Rotor Position Estimation Error Of Permanent Magnet Synchronous Motor

In recent years,the vector control method of permanent magnet synchronous motor has been widely used in motor drive systems because of its simple method and easy implementation.Among them,the sensorless control technology,while ensuring the system control effect,has the characteristics of reducing costs and saving space,and has become the main research direction in the field of permanent magnet synchronous motor drive control.However,affected by the nonlinearity of the inverter and the spatial harmonics of the motor’s own magnetic field,harmonics will appear in the stator current,and the motor torque will fluctuate.Obvious harmonic errors will appear in the position information estimated based on the model method,which will affect the result of coordinate transformation,cause inaccurate decoupling,cause additional harmonic losses,and make the motor’s operating effect worse.In response to this problem,this paper further studies the motor rotor position estimation error suppression strategy based on the position sensorless control technology of the sliding mode observer.Firstly,under the assumed ideal conditions,the mathematical model of the permanent magnet synchronous motor is derived.The principle of closed-loop vector control is studied,and several commonly used control schemes are introduced.A sliding mode observer is designed to estimate the position information of the motor to realize the sensorless drive control of the motor,and its effectiveness is verified in Matlab/Simulink.Secondly,a rotor position estimation error suppression strategy based on a reduced-order generalized integrator is proposed.Based on the traditional sliding mode position observer,this method uses a reduced-order generalized integrator to replace the low-pass filter in the traditional sliding mode observer,and filters the estimated back EMF to achieve the purpose of extracting the fundamental wave and suppress higher harmonics with zero amplitude attenuation and no phase delay.And the rotor position of the motor is obtained by using a quadrature phase-locked loop.The proposed method in this paper is easy to design,insensitive to parameters,and has outstanding steady-state performance.It can effectively suppress the rotor position estimation error,reduce torque ripple,and improve the control effect of the drive system.Finally,the position observer based on the reduced-order generalized integrator and the position observer based on the second-order generalized integrator are modeled and simulated in Matlab/Simulink,and the corresponding tests are completed on the1.5k W IPMSM drive system bench test platform.The steady-state and dynamic operating experiments verify the rotor position estimation error suppression strategy studied in this paper.Through comparative analysis,the rotor position estimation error suppression strategy based on reduced-order generalized integrator filtering in this paper can effectively suppress harmonic ripple,reduce torque ripple,suppress position estimation error,and achieve better control effects.