Adaptive Kalman Filter Observer-Based Control Strategy for Time-Varying Suspension System of 12/14 BSRM

The magnetic flux distribution of 12/14 BSRM creates dynamic variations across the stator-rotor air gap during rotor rotation. Consequently, the electromagnetic suspension force depends not only on the control current and the displacement of rotor but also varies with the angular position of the rotor, manifesting distinct time-varying nature. The time-varying suspension system faces issues such as lower suspension accuracy and reduced resistance to disturbance. This paper proposes a control strategy based on a nominal feedback model (NFM) and an adaptive Kalman filter observer (AKFO). The core idea of the proposed control strategy is to equivalently convert the time-varying suspension system into a time-invariant suspension system. Specifically, a dual closed-loop control system is designed for the time-varying suspension force, incorporating NFM independent of rotor position and AKFO. The NFM facilitates the design of a double closed-loop, while the AKFO can compensate for the discrepancy between the NFM and the real time-varying suspension force model. The performances of the proposed strategy and traditional strategy are compared through simulations and experiments.