Development of an Experimental Scaled-Down Frequency Dependent Transmission Line Model

The penetration of power electronic based equipment in the power grid has increased the co-occurrence of electromechanical and electromagnetic transients. Significant research efforts have been focused in the last decade to study these interactions. Frequency dependent transmission line models are indispensable to understand such interactions. This paper describes a systematic procedure for the development of an experimental scaled-down 220 V frequency dependent transmission line model of a 230 kV transmission line. A reduced order lumped parameter frequency dependent transmission line using modal transformation is derived for the 230 kV transmission line and scaled-down to 220 V. Clarke and inverse Clarke transformations are implemented using specially designed 1- Φ transformers. The inductances of the scaled-down model are realized using amorphous cores. Line energization, balanced, and unbalanced fault studies are carried out using the experimental line. The experimental results are compared with the simulation results of a universal line and a constant parameter π-model using EMTP-RV. The proposed experimental line properly captured important features of the frequency dependent line such as smoother wave shape during energization, traveling time, currents, and voltage magnitudes during the fault and after the fault removal.