Robust sparse network equivalent for large systems: part I-methodology

This paper deals with the calculation of a sparse network equivalent (SNE) for the analysis of electromagnetic transients in large systems. The main feature of the new approach is the enforcement of sparsity, stability, passivity, and accuracy at specific frequencies of the equivalent. The procedure is based on time-domain fitting with quadratic programming to enforce the constraints. The SNE can be interfaced with transient calculation programs directly in time domain. Results are presented in the companion paper.