Research On Position Sensorless Control Of Permanent Magnet Synchronous Motor Based On Sliding Mode Control Method

Permanent Magnet Synchronous Motor(PMSM)has many advantages such as simple structure and high power density.PMSM has broad application prospects in fields such as new energy vehicles and industrial production.However,PMSM is a multi-variable,strongly coupled nonlinear system.The traditional control methods cannot meet the requirements of high-performance control.In addition,the use of mechanical sensors to obtain rotor position information has higher requirements on the use environment of the system.Therefore,it is of great significance to study the control strategy of PMSM.This article applies Sliding Mode Control(SMC)to the PMSM control system to achieve PMSM high-precision control and position sensorless control,which has both theoretical and practical application values.First,classify the rotor structure of PMSM,and establish a mathematical model of PMSM through coordinate transformation theory.Furthermore,the block diagram of PMSM control system adopting vector control strategy is given,and the realization process of Space Vector Pulse Width Modulation(SVPWM)is explained.Secondly,in view of the contradiction between reaching speed and system buffeting in the exponential reaching law,a new reaching law with terminal attractor is designed,and take a typical second-order system as an example to analyze the control performance of the new reaching law.Then the new reaching law is introduced into the PMSM control system,and the sliding mode controller is designed.Build a simulation model and compare PI controllers to verify the superiority of the sliding mode controller.Then,in order to enhance the adaptability of PMSM control system to the environment,a sliding mode observer is used to design the PMSM position sensorless control system.Aiming at the high-frequency chattering caused by the switching function and the phase delay caused by the low-pass filter,a continuous function and back-EMF observer are introduced to construct an improved sliding mode observer.In addition,when extracting the rotor position information in the back EMF,in order to avoid the influence of the speed on the bandwidt,a normalized phase-locked loop is designed to improve the estimation accuracy.Through simulation experiments,the effectiveness of the improved sliding mode observer in chattering suppression and estimation accuracy improvement is verified.Finally,TMS320F28335 is used as the main control chip to build the PMSM control system experimental platform.The PMSM control strategy based on sliding mode control method is experimentally verified.