Simulation of frequency-dependent elements via a Rational Modeling of Multiport Systems

Employing an admittance matrix in the frequency domain by rational functions for power transformers is a well-known method which improves calculation efficiency. This model must be passive in order to avoid unstable time domain simulations. All of the methods have made efforts to overcome the problem of preserving the passivity of the final model. In this paper a similarity transformation matrix which better reveals the eigenvalues of the admittance matrix is presented. The chosen transformation preserves the passivity and symmetry of the original data.

Keywords:

Electromagnetic Transients , network equivalent , Passivity Enforcement , Pole-residue Model , vector fitting