Types of ring network cabinets

Common ring network cabinets can be divided into four categories according to the classification of insulating media.

1. Air-insulated type: This kind of ring network cabinet uses air as the main insulation medium, and the load switches installed inside mainly include gas generation type, compressed air type and vacuum type. Among them, gas production and compressed air type have been basically eliminated because of their low reliability. At present, most common air-insulated cabinets use vacuum load switches, but because of the limited air insulation performance, the cabinet body is usually large.

2.SF6 gas insulated type: This is the most widely used type at present. It uses SF6 gas with excellent performance as insulation and arc extinguishing medium, and has the advantages of small volume, compact structure, high reliability and small maintenance. SF6 load switch can easily realize "three positions" (on, off and grounding).

3. Solid insulation type: This is a relatively new technology. The vacuum interrupter and conductive connectors are encapsulated with solid materials such as epoxy resin, which greatly shortens the insulation distance between phases and the ground. Its volume can even be smaller than SF6 cabinet, and it avoids the use of greenhouse gas SF6, which has obvious environmental protection advantages and broad development prospects.

3. Environmental protection gas insulation type: In order to cope with the greenhouse effect of SF6, in recent years, the industry began to use environmental protection gases such as nitrogen and dry air as insulation media. This is one of the future development trends.