Research On Position Sensorless Of Coil-assisted Reluctance Brushless DC Motor

The coil assisted reluctance brushless DC motor(CAR-BLDCM)is composed of two sets of stator/rotor salient pole structures related to magnetic poles,and the auxiliary coil structure is added to the auxiliary excitation,which solves many problems caused by the inherent defects of the permanent magnet,Its biggest advantages are strong structure,strong reliability and high temperature resistance.Stable operation of the motor requires real-time and accurate rotor position information,the addition of position sensors not only increases the complexity of the system,but also reduces the reliability of the system.According to the special auxiliary coil structure of the motor,a new control strategy without position sensor is proposed in this paper.First of all,this thesis analyzes the connection between induction electromotive force of three-phase stator and rotor position when the auxiliary coil is connected with high frequency current pulse through multiple groups of ANSYS static and dynamic simulation,and summarizes the judgment basis of the initial on-phase when the motor starts and the next on-phase when the motor is running.Then,according to the judgment basis of rotor position,a sensorless control method based on induction electromotive force of three-phase stator is proposed,through the cooperation with speed PID and current chopper control,a joint simulation platform based on Maxwell,Simplorer and MATLAB is built.Through simulation,the current,speed and torque characteristics of the motor in the start-up phase and stable operation phase are obtained,which verifies the effectiveness and reliability of the control system in the simulation.Finally,based on the simulation theory of the control system,the TMS320F28335 is used as the control core to build the motor experiment platform.The ccs6.0 is used to achieve the programming control,and the parameters of the motor experiment are collected to verify the effectiveness and reliability of the sensorless control strategy based on the induction electromotive force in the experiment.