Computation technology of finite formulation method on electromagnetic field in electrical machines

Finite formulation method (FFM) is a novel numerical calculation method based on integration method and global variable conceptions. As so far, the method is mainly used in electromagnetic wave scattering problem of simple object and static electromagnetic field of regular shape. In this paper, the application of this method is extended into complex shape objects - electrical machines. An improved meshing and mapping method on primary and dual grid is put forward. Through this way, the program efficiency and calculation precision have been improved under condition of multi-medium objects and abnormity shapes. The FFM calculation results of an electrical machine are compared with finite element method and experiment data.