Research on Sensorless Control of Permanent Magnet Synchronous Motor

For the information of the rotor position of the permanent magnet synchronous motor position sensorless control system, the calculation method of different rotor positions of the motor under high speed and low speed is proposed. In the low speed state, the rotor information cannot be extracted because the back electromotive force on the stator is too small. The rotor position information can be obtained by the high-frequency voltage injection method. When the motor is in the medium-high speed operation state, the sliding mode observer method is introduced, and the rotor position information of the motor can be estimated. Finally, the rotor speed estimated by the sliding mode observer is obtained by simulation. The accuracy of the rotor position.