Active disturbance rejection control of a bearingless permanent magnet slice motor

Abstract Bearingless permanent magnet slice motor has the advantages of easy stator-rotor isolation, no contact, simple structure, and high integration, which is a significant feature in the ultra-pure field of biology, chemistry, medical treatment, semiconductor manufacturing, aerospace, and other applications, as well as high-speed drive field. To realize the control of a bearingless permanent magnet slice motor, the mechanism of torque control, as well as suspension control, is systematically analyzed. On this basis, a simplified control parameter design method for decoupling torque and suspension is proposed, and the parameter tuning rules are given. For the problem of insufficient anti-disturbance performance of the suspension control under the traditional linear active disturbances rejection controller (LADRC), an improved LADRC strategy based on known disturbances is proposed, and an expansion state observer (ESO) with partially known disturbances is designed. The suspension accuracy and robustness of the system are verified by simulating the motor control with a Matlab/Simulink module. Finally, the improved LADRC control is used in a BPMSM prototype. The simulation and experimental results show that the improved LADRC control with the addition of known perturbations effectively improves the suspension control stability and accuracy compared to the traditional LADRC control.