Sensorless Control For Surface Permanent Magnet Synchronous Motor And Detection Of Initial Position

In this thesis, the work concentrates on the study of surface permanent magnet synchronous motor (SPMSM) drive system without mechnical sensors. Fristly mathematical models of SPMSM are set up based on the motor electromagnetism, with these models the i_d=0 control strategy is used to accomplish the close loop. Secondly PWM technology based on space vector is introduced. And it's important to derive a scheme of PWM calculation for DSP from SVPWM modulation technique. All in all the key point is how to estimate the rotor speed and position.Here a method based on the model reference adaptive system(MRAS) is presented to estimate the speed and position. The MRAS stabilization is guaranteed by the H_∞ norm. With the help of matlab/simulink, the comparison between the motor controlling with sensor and without sensor is very useful to analyse the estimation strategy. The results show that it works well and the robustness against parameter's deviation is very strong.TMS320F240 type Digital Signal Processor(DSP)is used to control the SPMSM. But before starting the rotor initial position must be detected, the voltage pulse vector method is a proper scheme, the immunity from the motor paramete deviation is the advantage of the method.