Improvement calculation method of static magnetic field based on equivalent magnetic circuit method

With the development of magnetic materials, application of magnetic machinery has attracted extensive attention. In design and optimization of the magnetic machinery, calculation of magnetic field is particularly important. The equivalent magnetic circuit method (EMCM) has merits of simple modeling, small amount of calculation and extensive applicability; thus it is widely used in calculation of magnetic field of the magnetic machinery. However, computational accuracy of the existing EMCM for calculating magnetic reluctance at the parallel node of the magnetic circuit (MC) needs to be improved. Based on the EMCM, a calculation method of linearization decomposition of MC parallel nodes is proposed in this paper. According to the virtual distribution of magnetic induction lines, the parallel MC is decomposed into independent series serial magnetic circuits (MCs) by using an equivalent magnetic charge method. This calculation method consists of the following specific steps: simplification of magnetic poles (MPs) based on the equivalent magnetic charge method, planning MCs based on EMCM, distributing MCs linearly based on Coulomb's Law of magnetic field, calculating the magnetic reluctance of MC to obtain the intensity of static magnetic field. For a typical structural case given in this paper, the relative error between the theoretical calculation value and the computer simulation value is less than 3%.