Research On Sliding-mode Observation And Control Strategy For Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in modern motor drive system because of its strong reliability,high control accuracy and high energy density.With the shortcomings of permanent magnet synchronous motor with mechanical position sensor control system appearing in practical applications,the permanent magnet synchronous motor control system based on position sensorless is becoming an important research field.Therefore,it is necessary to carry out research on permanent magnet synchronous motor control system based on position sensorless technology.Firstly,based on the traditional second-order sliding-mode observer,a full-order sliding mode observer for permanent magnet synchronous motor(PMSM)is established by designing a hyperbolic tangent function with variable boundary layer and taking stator current and back-EMF as state variables,which can eliminate sliding-mode chattering and improve the observing accuracy of rotor position.Then,the position information of the rotor is estimated by designing a phase-locked loop algorithm,and the anti-disturbance performance of the effective observer to high frequency noise is obtained.Secondly,based on the sliding-mode control theory,using the exponential reaching law,combined with the extended state observer(ESO),the anti-disturbance sliding-mode speed controller of permanent magnet synchronous motor is designed.The disturbance information observed by the extended disturbance observer is subjected to feedforward compensation to reduce the sliding-mode switching gain,which is beneficial to the reduction of system chattering.Then,the simulation is carried out by Matlab/Simulink to verify the observation effect of the full-order sliding-mode observer designed in this paper,and the simulation is compared with the conventional second-order sliding-mode observer.In addition,the PI control system of PMSM,the sliding-mode speed control system based on the conventional exponential reaching law and the sliding-mode speed control system based on the reaching law designed in this paper are compared and simulated.Finally,the experiments are carried out on the hardware experimental platform based on TMS320F28335 to verify the effectiveness of the full-order sliding-mode observer and anti-disturbance sliding mode speed controller designed in this paper.