Combined Field/System Simulations of Low-Frequency Devices in Time Domain based on Adaptive Nonlinear Reduced Order Models

This paper outlines the robust construction of nonlinear reduced order models tailored for magneto(quasi)static approximations of Maxwell's equations in order to achieve a computationally efficient imprint into a coupled field/system simulation in time domain. To this end an adaptive, error bounded model order reduction technique based on spatial finite element discretizations has been developed. With regard to the nonlinear operator a two step procedure is proposed. The first step is an approximation of the nonlinearity itself in an affine form while the second step is applying a projection based model order reduction by means of a standard reduced basis scheme. The proposed technique will be verified by typical low-frequency applications, such as transformers.