Systems and line routes
The overall system length of the grid of Austrian Power Grid AG is over 6,700 km. It is divided into three voltage levels: 380 kV, 220 kV and 110 kV.
A "line system" or, in short, "system" refers to a set of three phases (= three conductors) which are needed to transport energy. The terms "three-conductor system", "three-phase system" or "rotary current system" are also frequently used.
A high-voltage pylon can carry one or several systems.
380 kV: the extra-high voltage level
Conductors heat up when transporting electricity thus leading to electricity transmission losses. These transmission losses decrease with higher voltage levels.
For this reason, 380-kV-lines are used as standard to transport high transmission loads over long distances.
Transformers and switching stations
To supply energy to households, the voltage must be transformed to a lower level near the consumer centers. This takes place in substations. Austrian Power Grid AG operates over 58 substations in Austria.