| Abstract: |
| Current and voltage waveforms recorded by intelligent electronic devices (IEDs) are more useful than just
performing post-fault analysis. The objective of this paper is to present techniques to estimate the zero-sequence line
impedance of all sections of a three-terminal line and the Thevenin equivalent impedance of the transmission
network upstream from the monitoring location using protective relay data collected during short-circuit ground
fault events. Protective relaying data from all three terminals may not be always available. Furthermore, the data from
each terminal may be unsynchronized and collected at different sampling rates with dissimilar fault time instants.
Hence, this paper presents approaches which use unsynchronized measurement data from all the terminals as well as
data from only two terminals to estimate the zero-sequence line impedance of all the sections of a three-terminal line.
An algorithm to calculate positive-, negative- and zero-sequence Thevenin impedance of the upstream transmission
network has also been presented in this paper. The efficacy of the proposed algorithms are demonstrated using a test
case. The magnitude error percentage in determining the zero-sequence impedance was less than 1% in the test case
presented. |
| Key words: Zero-sequence, Three-terminal line, Thevenin Impedance |
| DOI：10.1186/s41601-018-0108-y |
|
| Fund: |
|
