1. High-voltage circuit breakers

Since the beginning of the 20th century, numerous techniques have been developed to interrupt the current. We will describe here only the most recent, which use compressed air and SF ₆ as the cutting agent. These techniques have supplanted cut-off in atmospheric air or oil, which were used previously.

For a long time, oil interrupting technology was used for MV and HV circuit breakers. Up until the end of the 1970s, it provided an economical solution to most network requirements. At the time, high breaking capacities could only be achieved with compressed-air circuit breakers.

Subsequently, SF ₆ was preferred as a breaking agent due to the limitations of oil circuit breakers in breaking capacitive currents and the disadvantages associated with the...