Application of Frequency-Partitioning Fitting to the Phase-Domain Frequency-Dependent Modeling of Overhead Transmission Lines

This paper shows that a previously proposed linear-system identification method based on frequency partitioning and adaptive weighting can be successfully applied to the phase-domain frequency-dependent modeling of overhead transmission lines for electromagnetic transient simulations. As the framework of the phase-domain modeling, the universal line model is used, and the frequency responses of the characteristic admittance and propagation function matrices are realized by linear equivalents obtained by the identification method mentioned before, instead of the well-known Vector Fitting method. In this paper, numerical techniques to enhance the identification method for this phase-domain line modeling application are also presented. For validation, the proposed approach is applied to modeling an existing 500-kV double-circuit transmission line. The effectiveness of the numerical techniques for enhancements are shown through the modeling process, and transient waveforms obtained by the proposed approach are compared with those by the rigorous Laplace transform method and with a field-test result.