1. Benefits of current limiting

A handling error, a part falling onto bare busbars, a storm causing power lines to touch each other, lightning striking a pylon: these are just a few examples of events that can lead to a short-circuit-type fault in an electrical network. Very high currents can then occur, up to 20 to 30 times the rated current, the maximum steady-state value. The electrodynamic forces, proportional to the square of the current, become extremely high and can damage or even destroy the equipment (figure 1 ), even though it is theoretically designed to withstand such extreme forces (400 to 900 times higher than in normal operation). Joule losses are also considerable, and can lead to dangerous temperature rises if the fault persists. In general, especially on high-voltage networks, the fault current...