Conference paper
Distance Protection Impedance Measurement for Inhomogeneous Multiple-Circuit 400/150 kV Transmission Lines with Shared Towers
Combined transmission lines where different voltage levels shares same towers are used in transmission systems in order to save way of right. Faults between different voltage levels results in complex fault current distributions due to mutual couplings and the fact that the faulted phases no longer are interconnected in a simple way but via transformers and infeed from remaining parts of the network.
Distance relay measured fault loop impedance shows wide ranges of variations for both phase-phase loops as well as phase-earth loops. No simple relations exist. Simulation models can be used to study fault loop impedance for combined faults and thereby shed light on relay trips. This study uses actual fault records, analytical method and PSCAD simulation studies to analyse combined faults in an existing 400 and 150 kV transmission line owned by Danish TSO Energinet.dk.
The results clearly show that an accurate modelling followed by fault loop impedance calculation is possible. Selected results show that fault loop impedance can be located in unexpected regions of the complex R-X plane.
Language: | English |
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Publisher: | Institution of Engineering and Technology |
Year: | 2016 |
Pages: | 1-6 |
Proceedings: | The 13th IET International Conference on Developments in Power System Protection |
ISBN: | 1785611380 , 1785611399 , 9781785611384 and 9781785611391 |
Types: | Conference paper |
DOI: | 10.1049/cp.2016.0027 |
Danish TSO Energinet.dk Distance protection PSCAD simulation combined faults complex R-X plane complex fault current distribution distance protection impedance measurement distance relay electric impedance measurement fault currents fault loop impedance fault loop impedance measurement inhomogeneous multiple-circuit multiple circuit towers mutual coupling phase-earth loop phase-phase loop poles and towers power system CAD power system interconnection power system measurement power transformer protection power transmission faults power transmission lines power transmission protection powers system inteconnection relay protection shared tower transformer transmission line voltage 150 kV voltage 400 kV