Equivalent permeability method for multiple machine analysis by a single 2d-FEA model

In multiple machines systems, different electrical machines are interconnected from the mechanical and/or electrical point of view. The paper proposes an original methodology to analyze the whole system by means of a single 2d-FEA model, avoiding the need to approach very complex three-dimensional finite element simulations or co-simulation of separated bi-dimensional models. The proposed equivalent permeability method easily allows solving the problem of different stack axial lengths of the electrical machines, that represents the real limit of most of the today commercially-available 2d-FEA software. The basic theory of the proposed methodology is presented and validated by the case of study of a wound field synchronous generator excited by a rotating exciter.