Transmission line simulation for transient network analyser at Virginia Tech

Abstract

A general purpose cascaded pi section representation of a transmission line for a Transient Network Analyzer was designed. The pi sections modeled single and double circuit lines at 34.5, 69, 138, 345 and 765 KV levels. Representations of mutual impedances produced by nontransposition and mutual impedances and electrostatic coupling in double circuit lines are included in the model.

Line data was collected for the above mentioned transmission line configurations. Impedance and capacitance matrices were calculated for each line. The matrices were scaled to model voltage levels. Equations were derived relating these matrices to model component values. Inductors were designed for the model. Finally, the pi sections were built and tested.

Test results indicate steady state responses were generally correct to five percent. Maximum steady state error measured was 8 .6 percent. Results from the transient response tests were indicative of lines represented by very few pi sections.