Influence of temperature on the stiffness coefficient of AMB electromagnetic force

Active magnetic bearings (AMBs) have significant advantages over conventional rolling-element bearings in high-temperature rotating machinery, including lubrication-free operation, reduced cooling requirements, and compact structural design. However, elevated temperatures induce thermal expansion of bearing components and alter material electromagnetic properties, consequently affecting their load-bearing characteristics. Understanding temperature influence on AMB electromagnetic force is important for accurate dynamic prediction and optimal control performance. This work presents a parameter identification method that requires only rotor vibration displacement and coil current data, eliminating the need for specialized testing equipment. By placing the AMB-rotor system in a heating device, the variation law of electromagnetic stiffness at different temperatures is obtained, and the influence mechanism of temperature on electromagnetic force is explained through simulation analysis. The research results can be used for dynamic modeling and control optimization of AMB systems in high-temperature environments.