High Speed Precision Control Technology of Permanent Magnet Synchronous Gyro Motor

For a high-speed rotating gyro motor, improving its speed accuracy can reduce the orientation error and achieve accurate positioning of gyroscope. Traditional gyro motors use hysteresis gyro motors. Yet due to their higher efficiency and better thermal stability, permanent magnet motors gradually replace hysteresis motors. At present, domestic research on gyro motors mainly focuses on permanent magnet brushless DC motor (BLDCM) and permanent magnet synchronous machine (PMSM). The main control methods are concentrated in the field of sensorless control technology, among which the commonly used sensorless control method is the sliding mode observer (SMO) control method. Therefore, in recent years, various control methods of new sliding mode observer have been proposed at home and abroad to improve the control accuracy of permanent magnet motors. This paper is different from the traditional sensorless field oriented control (FOC) of SMO method with position phase-locked loop(PLL), and proposes a “four-stage” control strategy. The PMSM with multiple poles and small inductance is used as the controlled object. The SMO control method is used to achieve closed-loop acceleration control. When the rated speed is equivalent, the stator voltage phase-locked link is switched to improve the gyro motor's stability accuracy at a steady speed of 30000rpm.