Reseach On Speed Tracking Control Strategy For Permanent Magnet Synchronous Motor Based On Flux Observer

Compared to other motors, permanent magnet synchronous motor(PMSM) has many advantages and characteristics. So PMSM has been widely used in many occasions. But for the vector control of PMSM, the rotor speed and pole position of PMSM is generally required as feedback information. Many problems exist when the conventional mechanical sensors are used. Therefore, the research on sensorless control of PMSM technology is gaining more and more attention. This paper study the sensorless speed tracking control problem of surface mounted permanent magnet synchronous motor(SPMSM).In order to achieve sensorless control of the PMSM, a mathematical model of the PMSM for sensorless speed tracking control is established, based on the PMSM sensorless vector control system analysis.For the speed tracking system of a certain SPMSM, the sensorless speed tracking control problem based on the flux observer is studied. Based on the analysis of the feasibility that stator flux is used to estimate the rotor speed of the PMSM, design the speed observer based on the flux observer and the convergence analysis of speed observer were carried out. On this basis, the design of the sensorless speed tracking controller of PMSM to achieve the rotor speed track the speed reference trajectory is finished, and the results of computer simulations demonstrate the effectiveness of the controller which is designed in this chapter.For the SPMSM with uncertain load torque and resistance, a sensorless speed tracking adaptive controller is designed. Considering the existence of the uncertainties of resistance and load disturbances when the motor is running, a nonlinear adaptive controller that includes adaptive speed observer, speed tracking controller and the parameter adaptive laws is designed, which achieves the rotor speed of PMSM track the desired speed trajectory. Simulation results show that the controller is able to ensure an accurate estimate of the speed and precision tracking, even in the presence of parameter variations and load disturbance.