Parameter Estimation for a 500 kV Overhead Transmission Line and Analysis of Dead Time Prior to Single-Phase Automatic Reclosing Based on Synchrophasor Measurements

The validation of equivalent circuit parameters for various power system components remains an important task in power system research. Overhead transmission line parameters available in data sheets may not be correct, particularly for lines having been operated for a long time. In addition, both series and shunt equivalent circuit line parameters can experience deviations as a result of different weather conditions and line loading. Synchrophasor measurements provide the possibility to carry out “passive” monitoring and collect data to compute equivalent circuit line parameters under various power system conditions. Phasor measurement units capturing data from lines operating at 330 kV and above process line currents and voltages (instead of busbar voltages). This provides for continuous monitoring of single-phase automatic reclosing. In this study, synchrophasor measurements are applied to estimate equivalent circuit parameters for the 500 kV Taman – Kubanskaya line as well as to thoroughly analyze a set of conditions on the line reflecting a short circuit followed by a successful line reclosing. All calculations and conclusions are formed on the basis of real data archives containing synchronized vectors of voltages and currents for single-sided switching modes of 500 kV Taman – Kubanskaya line, as well as a short circuit on this line with successful single-phase automatic reclosing. As a result, the capacitive conductivities of the direct and zero sequences, as well as the inductive impedance of the direct sequence were verified. In addition, vector diagrams in the dead time mode of line reclosing were constructed and analyzed in detail, as well as the criteria were considered, which made it possible to perform an a priori assessment of the success of automatic line reclosing according to the synchrophasor measurement data.