Research On Position Sensorless Control Algorithom Of PMSM Based On Sliding Mode Observer

General sensor-based permanent magnet synchronous motor control methods can no longer meet the needs of life production applications.How to control the permanent magnet synchronous motor smoothly under sensorless conditions has become a research direction for scholars and technicians.In this paper,the following research is conducted for speed sensorless control based on adaptive and improved sliding mode observation algorithm:The basic wave mathematical model of the surface-mounted three-phase permanent magnet synchronous motor is established in the natural coordinate system and the synchronous rotating coordinate system.An incremental encoder is used as a position feedback element to design a space-based three-phase permanent magnet synchronous motor space vector control structure based on rotor field orientation,and a simulation model and an experimental platform are constructed.Both simulation and experiment prove that the system has good performance.Static characteristics and load capacity.Based on the rotor field-oriented of PMSM decoupling model and variable structure control theory,the traditional sliding mode observer algorithm is designed and simulated.It is proved that the traditional sliding mode observer algorithm is feasible,but there is chattering phenomenon,and the motor parameter sensitivity,etc.problem.Aiming at the existing problems,an improved adaptive sliding mode observer algorithm is designed and adaptive parameters are selected to suppress the chattering phenomenon and reduce the sensitivity to the motor parameters.The simulation and experiments show that the adaptive sliding mode observer is effective.The traditional sliding mode observer control method can not identify the initial position of the motor,and the observation effect at low speed is not good.Therefore,the rotor position estimation and saturation sliding mode function method based on software phase-locked loop is designed.At the same time,the I/F startup and sliding mode observer closed-loop smooth switching strategy are combined.The simulation results show that the chattering phenomenon of the motor is obviously suppressed.The accuracy of position and velocity estimation has been significantly improved,allowing the motor to run smoothly under a wide range of rated speeds,with excellent dynamic and static performance and resistance to load disturbances.This paper designs and compiles adaptive and improved sliding mode observation algorithm program using DSP chip(model TMS320F28335)of Texas Instruments Co.,Ltd.on the experimental control platform of permanent magnet synchronous motor,and finally achieves sensorless motor vector control.Experiments show that the surface-mounted three-phase permanent magnet synchronous motor drive system can run smoothly under no-load and load-carrying wide speed range,which proves the superiority of the improved algorithm and has practical value.