Modeling large-scale power systems with frequency-dependent transmission line models

The subject of this paper is the electromagnetic transient program (EMTP) model implementation of transmission lines for transient studies on large-scale power systems. Three models are investigated - the constant parameter (CP) model, the line constant frequency-dependent (FD) model, and the empirical FD model. The empirical FD model is a variation of the line constant FD model with the differences that it does not require the line constant routine and only needs power-frequency line parameters as input. The frequency dependence of the line parameters are calculated with empirical functions. Generally, the transients calculated with the empirical FD model are closer to the line constant FD model results in terms of RMS value and waveshape making the empirical FD model the preferred choice over the CP model if the line constant FD model cannot be used.