Application of frequency-partitioning fitting to the phase-domain frequency-dependent modeling of overhead transmission lines

摘要

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 (EMT) simulations. As the framework of the phase-domain modeling, the universal line model (ULM) is used, and the frequency responses of the characteristic-admittance and the propagation-function matrix are realized by linear equivalents obtained by the identification method mentioned above, instead of the well-known Vector Fitting (VF) 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 the modeling of 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 also with a field-test result.