Robust phase-domain transmission line representation based on time-domain fitting

This work presents a methodology for deriving a phase-domain transmission line representation based on time-domain fitting. A polynomial matrix in the discrete-time domain describes the resulting model. The robustness of the representation, its stability and passivity, is attained by imbedding a set of constraints in the solution of the fitting equations, which are solved using quadratic programming. Results demonstrating from transient simulations the features of the derived representation are presented for the case of an asymmetric, untransposed two-phase transmission line.