Circuit theoretical approach to couple two-dimensional finite element models with external circuit equations

This paper presents a new method to couple two-dimensional finite element models with circuit equations. The method is based on handling of the finite element model as a circuit theoretical multiport element. This multiport element is treated in the same way as ordinary nonlinear circuit elements within the Newton-Raphson iteration of the circuit equations. The method has been utilized in a simulator program for analyzing power electronic drives in the time domain. The electrical machine is modeled by the two-dimensional finite element method. The power electronic circuit and the connections of the windings of the machine may have an arbitrary topology which is given by a net-list file (SPICE-type input file). The applicability of the method is investigated with two example cases which are verified by measurements. According to tests, the method proposed provides an effective and reliable way to construct simulators including finite element modeling.