Sensorless Vector Control Of PMSM With An Adaptive Sliding Mode Observer

The advantages of permanent magnet synchronous motor are high power factor and large output torque,which are widely used in industrial fields.In the precise drive control of the permanent magnet synchronous motor,the rotor position information needs to be accurately obtained through the position sensor,but the position sensor is expensive and bulky,and the system has poor anti-high frequency noise interference performance.Based on the mathematical model of PMSM in three-phase static coordinate system and the FOC theory,the mathematical model of PMSM vector control system is determined by coordinate change and variable decoupling.The SVPWM algorithm is optimized.Aiming at the problem of rotor position and speed estimation of permanent magnet synchronous motor without position sensor control,based on the permanent magnet synchronous motor voltage equation and sliding mode variable structure theory,the back electromotive force feedback and saturation switching function are introduced to construct the adaptive sliding mode observer,and the rotor position and speed are estimated.After analyzing the stability of the adaptive sliding mode observer,the adaptive coefficients and discrete observer equations are determined.Adaptive sliding mode observer at the same time an accurate estimate of the rotor position can theoretically eliminate jitter sliding motions generated.The problem of zero-speed starting of the permanent magnet synchronous motor without position sensor is solved by the I/F three-stage starting method,and the switching process is optimized.A complete sensorless vector control system theory of adaptive sliding mode observer for permanent magnet synchronous motor is established.Based on the TMS320F28335 control chip,a position sensorless vector control system is designed.The above theory is implemented by software compilation in CCS compilation environment,and the hardware circuit of the system is designed according to the specific functions of DSP.Finally,the experimental platform of sensorless vector control system for adaptive sliding mode observer of permanent magnet synchronous motor is realized.Through the experimental platform built,the above theory is verified and analyzed.Permanent magnet synchronous motor under various operating conditions,adaptive sliding mode observers accurately estimate rotor position and effectively reduce system chattering;Good system stability,wide speed range and good dynamic response;Disturbing loads the system with strong anti-disturbance.The system can replace the permanent magnet synchronous motor with position sensor vector control system.