The ceramic shell vacuum arc extinguishing chamber is mainly composed of airtight insulation shell, conductive circuit, shielding system, contacts, corrugated tube and other parts. The shielding system of a vacuum arc extinguishing chamber mainly consists of a shielding cylinder, a shielding cover, and other components.
The main function of the shielding system is to:
1. Prevent the contact from generating a large amount of metal vapor and liquid droplets during the arc ignition process, contaminating the inner wall of the insulation shell, and avoiding a decrease in insulation strength or flashover of the vacuum arc extinguishing chamber shell.
2. Improving the electric field distribution inside the vacuum arc extinguishing chamber is beneficial for the miniaturization of the insulation shell of the vacuum arc extinguishing chamber, especially for the miniaturization of high-voltage vacuum arc extinguishing chambers.
3. Absorb a portion of the arc energy and condense the arc products. Especially when the vacuum arc extinguishing chamber interrupts the short-circuit current, most of the thermal energy generated by the arc is absorbed by the shielding system, which is beneficial for improving the dielectric recovery strength between the contacts. The greater the amount of arc generated material absorbed by the shielding system, the more energy it absorbs, which has a good effect on increasing the breaking capacity of the vacuum arc extinguishing chamber. The contact is the part where the arc is generated and extinguished, and it has relatively high requirements for materials and structure.