Analysis and Control of Self-Sensing Model of Isolated Axial Magnetic Bearing

In this paper, a displacement estimation strategy for axial magnetic bearing thrust disk considering eddy current effect is proposed. While greatly reducing the volume of magnetic bearings brought by the installation of displacement sensors, the axial magnetic bearings can work in harsh environments such as high pressure and corrosive liquids. Based on dynamic equivalent reluctance, an inductance model considering eddy current effect is established. Then, by deducing the relationship between inductance and the first harmonic amplitude of switching power amplifier, the displacement model of thrust disk is analyzed, and the first harmonic amplitude demodulator is established. Finally, the self-sensing experimental platform of axial magnetic bearing is built, and the correctness of the self-sensing model is verified by static linearity comparison experiment and dynamic suspension experiment.