Temperature measurement system for gas insulated transmission lines for an effective load scheduling of underground bulk power transmission

Abstract

Gas Insulated Transmission Lines are designed for underground bulk power transmission. They may be used to overcome potential bottlenecks in EHV transmission grids. They are designed for high ampacities and have high overload capabilities. By exploiting the latter, a load scheduling in the grid becomes easier. To do so the thermal status of the GIL has to be known. A temperature measurement system was developed and tested which allows an online measurement of the conductor temperatures during operation, enabling scheduling and handling of overloads.

Gas insulated transmission lines (GIL) with spare phase - new concepts for investment reductions

“…Depending on the application, a GIL system may carry between 2500 A (directly buried) and 4000 A (tunnel or outdoor installation) of continuous current [14]. The application of a thermal rating system allows even in the case of directly burying currents of up to 4000 A for operating hours with higher currents [15]. Therefore, for the replacement of OHLs for certain lengths with GIL, instead of applying a double system of GIL (6 phases) only a 3-phase system with a spare phase as described in section 2.1 may be applied.…”