vacuum circuit breaker

vacuum circuit breaker

"Vacuum circuit breaker" is named because both the arc extinguishing medium and the insulating medium of the contact gap after arc extinguishing are high vacuum; it has the advantages of small size, light weight, suitable for frequent operation, and no need for maintenance for arc extinguishing. The application in the power grid is more popular. The vacuum circuit breaker is an indoor power distribution device in a 3-10kV, 50Hz three-phase AC system. It can be used for protection and control of electrical equipment in industrial and mining enterprises, power plants and substations. In the places of maintenance and frequent operation, the circuit breaker can be configured in the middle cabinet, double-layer cabinet and fixed cabinet to control and protect high-voltage electrical equipment.

working principle

When the vacuum circuit breaker is in the closed position, its ground insulation is borne by the supporting insulator. Once a permanent ground fault occurs in the line connected to the vacuum circuit breaker, after the circuit breaker trips, the ground fault point is not cleared, and there is an electrical busbar. The ground insulation must also be borne by the vacuum gap of the breaker fracture; when various faults are interrupted, the vacuum insulation gap between a pair of contacts of the fracture must withstand the action of various recovery voltages without breakdown. Therefore, the insulating properties of the vacuum gap have become the main research topic to improve the fracture voltage of the arc extinguishing chamber and make the single-fracture vacuum circuit breaker develop to a high voltage level.