Electric network analysis including a region of finite element analysis

Magnetic field analysis using the finite element method in general requires current density to be a known quantity. An electric network, however, is usually driven by constant voltage sources and the currents are affected by the impedances not only in the circuit but also in the finite element analysis region which is connected to the circuit. Therefore, it is generally difficult to know the current density in advance. This paper proposes a general method for analyzing a magnetic field in an electric network. Expanding the signal flow graph (SFG) method makes possible the simultaneous analysis of an electric network and in its magnetic field; the network including the finite element analysis region is expressed by a SFG and the linear simultaneous equations of the SFG and those of the finite element method are combined. As a SFG can be constructed systematically for arbitrary network;the analyst need only prepare data regarding the connection of elements, their electrical characteristics, and the parameters of the finite element analysis region. In this paper, a two dimensional static magnetic field taking account of eddy current is considered and the proposed method is applied to the analyses of electromagnetic stirrer.