Abstract: To overcome the drawbacks of the conventional linear approximation method, the air gap reluctance, magnetic field distribution and magnetic force on the rotor of a new hybrid magnetic bearing are calculated with the integral method, and the calculated results of the two methods are compared with each other. The magnetic field distributions calculated by the above two methods are compared with those calculated by the finite element method. It shows that the results calculated by the integral and finite element methods are in good agreement with each other, but the error in linear approximation computation is large. The errors of the air gap reluctances and magnetic forces in linear approximation computation are related to the magnitude and direction of the rotor displacement. Although the errors of air gap reluctances are small, those of magnetic forces are no less than 12%. The integral method can efficiently improve the calculation accuracy of the air gap reluctance, magnetic field distribution and magnetic force, and are particularly helpful for the analysis and design of magnetic bearing.

Key words: Air gap reluctance, Hybrid magnetic bearing, Magnetic field distribution, Magnetic force, Relative error