Virtual Material Method for Enabling a Single 2D-FEA Simulation of Electrical Machine Sets

When two or more electrical machines are electrically and mechanically interconnected, the implementation of a single two-dimensional finite element analysis (2D-FEA) of the whole system is complex or even impossible. This is mainly due to the feature of commercially available 2D-FEA software to use a domain depth equal for all the electrical machines drawn in the geometrical 2-D model. For any typology of rotating electrical machines, the proposed "virtual material method" easily consents to change the actual axial stack length to an arbitrary value, opening the way to describe all the machines in a single geometrical model. In the paper, the complete theory of this original approach is reported and validated on permanent magnet, induction, and field-wound synchronous machines. The cases of study with two and three interconnected machines are also presented and the results compared with the cosimulation technique of their separated bidimensional models. The perfect agreements observed in the comparisons definitely prove the feasibility of the proposed solution.