Compared with the traditional SF6, N2 gas insulated network cabinet, the advantages of the environmental protection gas cabinet are:

First of all, it is the most attractive environmental protection performance. It uses dry air instead of traditional SF6, N2 and so on. It not only improves the insulation performance, but also does not pollute the air after release.

Secondly, it is its strong environmental adaptability. The main circuit components of the environmental gas cabinet are built in the inflatable compartment, the pressure is constant and is not affected by the altitude. It is especially suitable for high altitude areas. Compared with the FS6 ring network cabinet, its coverage will be more extensive without special design. Again, the size of the whole cabinet is greatly reduced. Because the insulation performance of the dry gas is far superior to the SF6 and N2 gas, its electrical gap is far less than that of the SF6 ring network cabinet. Because of the small electrical gap, the size of the air insulated ring net cabinet is much smaller than the traditional ring network cabinet with the same voltage level. At the same time, the distance between the insulation after the insulation is only 1/3 of the air insulated cabinet, and the size of the ring net cabinet is greatly reduced.

Finally, the air insulated ring cabinet is more flexible and simple in operation, and is safer to use. If it can be popularized in a large area, the price of the air insulated ring cabinet can be quickly compared with the SF6 ring cabinet. At present, the dry air insulated ring network cabinet at the initial stage occupies only 10~15% share of the current ring cabinet market, but the prospect is limitless. Experts predict that in the next 10 years, dry air insulated ring cabinets will become one of the mainstream products of the environmental protection market in the future. China's urbanization promotes the development of environmental protection gas cabinet, and puts forward the requirements of high reliability, miniaturization, environmental protection and intellectualization for environmental protection gas cabinet.

Many foreign companies studied and developed environmental protection gas cabinets in the early years. They were mainly divided into European and Japanese models according to their structural characteristics. The European model is to use the vacuum interrupter as a quick connection to achieve the maintenance free function, and to cancel the design mode of the air insulation cabinet which is usually grounded by the grounding switch, in order to simplify the design and to improve the reliability and competitiveness of the product based on the simple and reliable principle. The Japanese mode is both the upper and the bottom and the cable side of the circuit breaker. Three position isolation knife, and cable side has quick grounding switch, and has cable test casing. Japan's design is safer, but the whole machine design and mechanical interlocking are too complex, and the product's economy is poor. In the design of the box, 3mm stainless steel sheet with laser welding is widely used in Europe, and 8mm and above thick carbon steel are commonly used in Japan.

In recent years, in order to adapt to these requirements, many types of gas cabinet have been developed and produced. The author discusses and compares several main insulation modes of medium voltage distribution cabinets on the market, and then puts forward a kind of extractable compact environmental gas cabinet, and analyses the structure characteristics, reliability and economy of this type of cabinet. The development of medium voltage switchgear provides a reference for the future. In the future, the environmental protection gas cabinet will be widely applied in the field of power.