Research On Position Sensorless Control For Surface Permanent Magnetic Synchronous Motor

Traditional AC servo speed control system requires sensors to detect real-time speed and position information of the motor, which have some drawbacks of cost rising and environment limit. In order to resolve the problems, sensorless technology has become a hot topic. Based on the salient effect of the surface permanent magnetic synchronous motors produced when high frequency pulse injection method is applied, the low speed running can be realized without sensors. Since the surface of paste-type permanent magnet synchronous motor itself does not have the saliency resulting in poor dynamic control performance and steady performance. To further improve the performance of the sensor less control system for the surface type permanent magnet synchronous motor at low speed. Based on fluctuating high frequency injection method, the permanent magnet synchronous motor control system without position sensor is designed and researched.Firstly,detailed analysis and presentation of the current position sensorless permanent magnet synchronous motor control technology are given. Through the establishment of a permanent magnet synchronous motor mathematical model, it was analyzed that the pulsating high-frequency voltage injection method for PMSM position sensorless vector control system.The error analysis of the high frequency injection method shows that there is a big error in the rotor position estimated by the traditional method of high frequency voltage signal injection.Secondly, based on the high frequency voltage injection method, the stability parameter algorithm of pole placement observer is designed, and the low pass filter considered the delay of the signal is designed. The simulation model was built by using Simulink platform, and the simulation results show that the improved dynamic performance and the stability of the system have been improved obviously.Finally, hardware and software for the system was designed. And the analysis of the main part of the hardware circuit theory, the function of the software were given. The motor starting, reversing, with load experiment were fulfilled, which proved that the system has a good dynamic performance and the validity of the design.