Research on Sliding Mode Control of An Active Magnetic Bearing High-Speed Motor Rotor

With the improvement of high-speed motor technical requirements, the PID-controlled Active Magnetic Bearings (AMB)-rotor system gradually shows its shortcomings. In this regard, this paper proposes to use sliding mode controller (SMC) to constrain the magnetic bearing. Based on the introduction of the AMB structure, this paper establishes a mathematical model of a single-degree-of-freedom(DOF) magnetic suspension rotor system, and designs PID control and SMC schemes respectively according to the mathematical model. According to the prototype parameters, the approach rate of SMC was selected, and a simulation model was built on the Simulink platform, simulation experiments were carried out for the step response and sudden disturbance of the system. Comparing the displacement output of the rotor under PID control and SMC, it can be found that the AMB high-speed motor rotor system under SMC can achieve stable suspension operation, and the system under SMC has better anti-interference ability and stronger robustness.

I. Introduction

Active Magnetic Bearings (AMB) uses sensors to detect the orientation information of the rotor at all times, and then adjusts the magnetic field force in the air gap through the control module and power amplifier, so that the rotor can levitate smoothly [1]. High-speed motors using AMB have been widely used in many fields, such as turbine engines, flywheel energy storage equipment, vacuum pumps, industrial equipment manufacturing, etc., due to their rotors having excellent characteristics such as frictionless, lubrication-free, and low loss [2].