Three dimensional field models of electrical machines

The paper discuses the numerical methods of electromagnetic field calculations in the electric machines. The 3D field model of electromagnetic phenomena is presented. The model consists of: (a) finite element (FE) equations for the magnetic field, (b) equations describing eddy-currents and (c) equations, which describe the currents in the machine’s windings. Moreover the FE equations are coupled by the electromagnetic torque to the differential equations of motion. Both scalar and vector potentials are considered. The FE equations are derived by using the notation of circuit theory. It has been shown that there are two types of circuit models associated with FE mesh: (a) edge networks for scalar potentials and (b) facet network for vector potential formulations. The descriptions of material properties in 3D FE space are reviewed. FE models of multiply connected conducting regions are discussed. Both thin and rod conductors are considered. Resistive models of multi-turn coils are described for which the potential T(0) is introduced. The electromagnetic torque calculation using FE models are presented