A Convenient Mesh rotation method of finite element analysis using sub-matrix transformation approach

This paper presents a novel sub-matrix transformation method on mesh rotation problems in the finite element analysis (FEA) of electric machines. This proposed approach is simple, convenient and readily implementable. For each rotor position, only the transformation matrix which has fixed regular pattern versus the rotor position displacement needs to be modified. Transformation matrices with first-order element, second-order element as well as with periodic and anti-periodic boundary conditions have been developed. By using sub-matrix transformation, the mesh coupling can be realized automatically, efficiently and with minimal computing burden, since all the coefficients of the FEA system equation are stored in the sub-matrixes and they do not need to be re-assembled for different rotor positions. Formulae derivation and theoretical analysis are presented together simulation results to verify the validity of proposed method.