Permanent Magnet Synchronous Motor Speed Sensorless Vector Control

As energy conversion device, electric motor is widely used in industry and daily life. Comparing with DC motor, AC motor obtains much more advantages, but it is not widely used in speed governing because of the limitation of AC motor control theory, microcontroller and electrical and electronic devices. Along with the development of control theory and technology, AC motor speed governing system develops quickly. As a type of AC motor, PMSM (Permanent Magnet Synchronous Motor) is of outstanding performance, low cost and high reliability, and is becoming hotspot of electric traction study.This paper carries out the theoretical research and mathematical deduction on key issues about PMSM such as vector control, non-sensor position and speed detection, and rotor initial position detection. Hardware circuit control program are designed, and are tested through experiments.Firstly, because of nonlinearity and strong coupling of PMSM, its flux linkage should be decoupled through coordinate transformation, to obtain favorable speed governing performance as DC motor, which is called vector control. id=0 control method is adopted and the theory is researched, which improves motor's control performance.Secondly, real-time rotor position detection should be carried out during PMSM vector control system's operation. Employing sensor increases system's cost and decreases its reliability, and non-sensor technology provides good solution for this. Therefore, non-sensor technology based on MRAS is researched theoretically, and the mathematical model is set up. Furthermore, the solutions to the problems existing in non-sensor position and speed detection are put forward.Thirdly, rotor initial position detection of PMSM is crucial for motor's start-up and its non-sensor operation. PMSM with different rotor structure has different method for rotor initial position detection. Since saturated-saliency-effect-based rotor initial position detection is of wide using range and high estimating accuracy, it is researched in this paper. The non-salient PMSM rotor initial position estimation is put forward and experiments are carried out, which verifies the detecting method.Finally, based on the theoretical research, a non-sensor PMSM vector control system with sensor employing ARM is designed. The hardwire circuit debugging and control programming are carried out, realizing the motor's normal operation with sensor.