A trajectory piecewise-linear approach to model order reduction for nonlinear stationary magnetic devices

In power electronics and electric machinery, finite-element based time-domain modeling has been used frequently. Generally, the time-domain modeling of magnetic devices is completed by solving a high order system at each time step. Fortunately, the full order state-space models can be reduced methodically without additional assumption. The method for reducing the order of magnetically linear system is presented in previous work. However, in the analysis of magnetic devices the problems are usually nonlinear due to the presence of ferromagnetic materials. In this paper, a nonlinear model of the magnetic devices is presented and reduced by using a trajectory piecewise-linear approach.