Accurate Identification Method of Rotational Inertia under Variable Load Conditions for High-speed Permanent Magnetic Synchronous Motor

The magnetically levitated turbo molecular pump (MLTMP) can create a high vacuum environment by driving a large inertia turbine composed of multi-stage blades. When the pressure of the vacuum chamber changes abruptly, it will cause a rapid change in the load torque. Due to the large inertia of the MLTMP, its response speed is slow when the load torque changes, which may reduce the pumping speed. The dynamic performance and control accuracy of large inertia system can be effectively improved by using rotational inertia to design speed loop controller. In order to identify the rotational inertia in real time and accurately, this paper proposes a rotational inertia identification method based on model reference adaptive system, which is derived using the continuous method and is suitable for the case of rapid change of load torque. Simulation results show that this method can accurately identify the rotational inertia of the motor with rapidly changing load torque and has good anti-interference ability.