Temperature dependent ampacity limit modelling of overhead power lines (TeKaF)
Scope of projectTeKaF stands for "Temperaturabhängige Kapazitätsausnutzung für Freileitungsnetze".
The capacity of today’s electric transmission system is limited by several constraints: the thermal rating of cables and overhead lines, voltage drop, and stability margin. In Switzerland and most of central continental Europe, the thermal limit is the main constraint. Bottlenecks are often the transit lines and the connection of large generating units.
The goal of the project is to deliver the necessary know-how that allows the grid operator to better estimate the remaining capacity (current) of each single line. The information needed is the maximum possible steady-state current value (or the maximum operating time for a given overcurrent), corresponding to the actual weather situation. The calculation of the maximum current value also takes into account the long-term behavior (conductor lengthening and loss of mechanical strength) of the line. The focus is on all aluminium conductors (Aldrey) as this is the main material used in Switzerland and not enough information is available for this type of conductor.