Distributed Magnetic Equivalent Circuit Modeling of Synchronous Machines

Abstract

This paper proposes a highly accurate and computationally efficient distributed magnetic equivalent circuit (DMEC) model for synchronous electric machines. The model - based on a two directional flux paths cell element - is derived in a general fashion in order to easily define different geometries. All the steps required for the DMEC definition and its non-linear resolution are detailed including the rationals behind the geometrical discretization, the setting of the excitations and the boundary conditions implementation. A comprehensive comparison between results obtained using DMEC and FEM is provided for three different machine types, namely surface permanent magnet (SPM) machine, permanent magnet synchronous reluctance machine (PMaSynRel) and a synchronous reluctance (SynRel) machine in a wide range of operation points. The computational advantage of proposed model is also investigated as function of the level of discretization and so accuracy of the estimated performance. The predictions of the proposed DMEC model are fully experimentally validated with an extensive test campaign on an off-the-shelf synchronous reluctance motor.