Research on Composite Control Method Without Position Sensor for Permanent Magnet Synchronous Motor at all Speed Ranges

In the context of extremely low-speed operation, where velocities are at their absolute minimum, sensorless technology encounters additional losses and delays in position estimation when controlling permanent magnet synchronous motors, especially as we venture into the higher velocity spectrum, where the model parameters have a significant impact. In light of this, this study adopts a new algorithm built upon the principle of injecting high-frequency signals, utilizing a pulse modulated high-frequency voltage signal injection method based on position tracking. Combining model reference adaptive control and improved high-frequency signal injection methods, this paper introduces a holistic sensorless control scheme designed for the complete range of speeds. We established a simulation model in the Matlab/Simulink environment and conducted comparative analysis of the results. The research found that the proposed comprehensive control strategy can effectively identify motor speed and rotor position information, achieve smooth transitions between different speed ranges, enhance the system's dynamic response capability and speed regulation, while also improving the system's reliability.