Application of fringing range method to micromagnetic bearing actuator design

The fringing range method developed earlier for two-dimensional (2-D) probl ems is extended in this paper to three-dimensional (3-D) cases and is used for analyzing a micromagnetic bearing actuator. Expressions for the air-gap permeances, as well as forces and torques, are derived that are suitable f or parametric analysis of the actuator design. With this approach, the air- gap permeances are also used in the magnetic circuit for calculating the ai r-gap magnetomotive forces, thus, allowing the development of a systematic procedure for magnetic bearing analysis and design. A design example is giv en to illustrate the application of the present approach.