Three-dimensional magnetostatic field calculation using integro-differential equation for scalar potential

An effective method for calculation of nonlinear three-dimensional magnetostatic fields is proposed. It is based on a numerical solution of the integro-differential equation for the total scalar potential. The main advantages of this method are that the problem has been formulated in terms of a scalar variable introduced only for regions filled with ferromagnetic materials and no artificial boundary conditions are required. The numerical algorithm which implements this method is described. Its application is illustrated with magnetostatic field calculation for C-magnets.