Dynamic Correction Model Considering Influence of Foundation Motions for a Centripetal Force Type-Magnetic Bearing

Conventional suspension forces modeling methods are usually only focused on the computation of the internal magnetic field of the magnetic bearing itself. However, the modeling accuracy is also affected by its actual application, especially for the magnetic bearing in moving situation, such as magnetic suspended flywheel battery system for electric vehicles. In this article, taking the centripetal force type-magnetic bearing as an example, a dynamic correction model considering influence of foundation motions is proposed, which has several submodels to cover as many driving conditions as possible. First, a universal static model based on spherical coordinate system is established. Then, the dynamic model is derived, which includes the control current, offset, and variables of foundation. Given the complexity and diversity of real-time operating conditions of vehicles will affect the calculation accuracy of variables of foundation, resulting in the increase of the error in single dynamic model. Therefore, the idea of foundational weight factor is brought up and fitted by analyzing the dynamic response laws of rotor under different foundation motions. Finally, the dynamic stiffness experiments and performance tests are carried out. The good experiment results show that the proposed model is more practical and has higher precision than traditional model.