High-voltage switchgear

This equipment is essential for the protection and safe operation, without interruption, of a high voltage power system, and is important because it is directly linked to the quality of the electricity supply.

High-voltage switchgear was invented at the end of the 19th century for operating motors and others electric machines.

In three-phase electric power, they only eliminate the phases where the fault current is flowing, which can pose a risk for both the malfunctioning devices and the people.

The international standard IEC 62271-100 defines the demands linked to the characteristics of a high voltage circuit breaker.

[7] The circuit breaker can be equipped with electronic devices to know at any moment their states, such as wear or gas pressure, and to detect faults from characteristic derivatives.

[8][9] To operate on long lines, circuit breakers are equipped with a closing resistor to limit overvoltages.

[10][11] They can be equipped with devices to synchronize closing and/or opening, to limit the overvoltages and the inrush currents from the lines, the unloaded transformers, the shunt reactances and the capacitor banks.