CPU-Time Reduction for Steady-State Solution in Time-Stepping FE Analysis of Rotating Machinery

In analyzing electrical apparatus excited from a constant voltage source such as rotating machines by the time-stepping Finite Element method, undesirable initial values often cause a large number of iterations and thus result in a long computing time. In this paper, with this background, we propose a novel acceleration method that improves the convergence characteristics of the time-stepping FE analysis for a motor excited from a constant voltage source. The proposed method enables us to sufficiently reduce the computing time by providing appropriate initial values to unknowns. In the method, the primary and secondary currents of an induction motor in steady-state operation are precisely estimated by means of both the equivalent circuit of a motor and the initial transient waveform of the currents obtained by the FE analysis, Finally, some numerical results, which demonstrate the validity of the proposed method, are also presented.