Abstract
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.
Original language | English |
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Title of host publication | Proceedings of 13th International Conference on Developments in Power System Protection 2016 (DPSP) |
Number of pages | 6 |
Publisher | Institution of Engineering and Technology |
Publication date | Mar 2016 |
Pages | 1-6 |
ISBN (Print) | 978-1-78561-138-4 |
ISBN (Electronic) | 978-1-78561-139-1 |
DOIs | |
Publication status | Published - Mar 2016 |
Event | The 13th International Conference on Developments in Power System Protection - The Sheraton Hotel, Edinburgh, United Kingdom Duration: 7 Mar 2016 → 10 Mar 2016 Conference number: 13 http://conferences.theiet.org/dpsp/ |
Conference
Conference | The 13th International Conference on Developments in Power System Protection |
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Number | 13 |
Location | The Sheraton Hotel |
Country/Territory | United Kingdom |
City | Edinburgh |
Period | 07/03/2016 → 10/03/2016 |
Internet address |
Keywords
- Power transformer protection
- Power transmission protection
- Power system interconnection
- Power transmission lines
- Relay protection
- Fault currents
- Power system CAD
- Power system measurement
- Power transmission faults
- Electric impedance measurement
- Poles and towers