Active Disturbance Rejection Control in Magnetic Bearing Rotor Systems with Redundant Structures

Area of Science:

• Mechanical Engineering
• Control Systems
• Electromagnetism

Background:

• Magnetic bearings offer energy savings over mechanical bearings in industrial settings.
• Redundant magnetic bearing-rotor systems face challenges from strong coupling, electrical, and external disturbances, degrading performance.
• Existing control strategies may neglect individual coil currents, limiting simulation accuracy.

Purpose of the Study:

• To enhance the anti-interference capabilities of magnetic bearing systems.
• To develop a control strategy that accounts for the current of each coil in redundant magnetic bearing systems.
• To improve the overall stability and performance of magnetic bearing-rotor systems under disturbances.

Main Methods:

• Established current and displacement stiffness models for magnetic bearings based on their working mechanism and nonlinear electromagnetic force.
• Constructed a dynamic rotor model and an equivalent control loop for the redundant magnetic bearing-rotor system.
• Designed a linear active disturbance rejection controller (LADRC) utilizing the inverse of the current distribution matrix (W^-1).

Main Results:

• The proposed LADRC combined with current distribution control effectively improves the anti-interference performance.
• Simulations demonstrated superior performance compared to the PID plus current distribution control strategy.
• The LADRC strategy enables accurate simulation by including individual coil currents.

Conclusions:

• The LADRC strategy offers a significant improvement in the anti-interference performance of redundant magnetic bearing-rotor systems.
• This approach provides a more robust and reliable control solution for magnetic bearings facing complex disturbances.
• The method validates the effectiveness of active disturbance rejection control in advanced magnetic bearing applications.