Analytical Modeling of Permanent Magnet Biased Axial Magnetic Bearing With Multiple Air Gaps

This paper proposes a permanent magnet (PM) biased axial magnetic bearing (MB) with multiple air gaps. However, the inherent complex structure makes finite-element analysis (FEA) very time-consuming. For the sake of simplifying the analysis, an equivalent magnetic circuit model together with the conformal mapping method and Laplace´s equation is developed. The conformal mapping method is employed to obtain the flux distributions in rectangular air gaps by accounting fringing effect, while the Laplace´s equation is used to predict the leakage flux surrounding PM rings. The developed analytical model is validated by FEA. Consequently, the design parameters in the axial MB are analytically determined.