The gas cabinet was first developed in Japan in the 70s and 80s of last century. Subsequently, the world developed the corresponding products, the main voltage grade was in 7.2-126kV, the earliest all bus, components, mutual inductor and so on were installed inside the sealed box. In 90s, the gas filling cabinet of 24-36kV has developed rapidly and mutual inductor. The class is placed outside the gas tank, and the solid interface insulation technology has been applied to high voltage element splicing. In 90s, China should also introduce and use this kind of technology. After ten years of development, the gas cabinet has been widely recognized by the users. Some domestic manufacturers probably seize the domestic market by introducing foreign technology and Sino foreign joint ventures around 2000. Well-known foreign manufacturers are mainly ABB, SIEMENS, Althom, Schneider, Hitachi, MITSUBISHI and so on, all big electric companies have 7.2 to 40.5kVC-GIS, and realize the full series of products. In the ten years of 2000 to 2010, the insulation technology of the gas tank, the heat dissipation technology, the sealing technology, the opening and breaking technology of the vacuum interrupter, the welding technology and the digital control, protection and monitoring technology have been developed rapidly.

The 1. ring network cabinet can be divided into air insulation and SF6 gas insulation according to the insulation structure.

The 2. ring net cabinet refers to the load switch cabinet for ring network power supply, and the load switchgear can be used for ring network type power supply, medium voltage demarcation chamber dispatching and medium voltage terminal substation power supply. The load switch cabinet is simple in structure, low in cost and small in volume, and most can be installed on the wall, usually only the fuse protection without relay protection.

The 3. is generally composed of three intervals: 2 loop cables in and out and one transformer circuit interval. The time of the ring cabinet is not long, but it has been widely used. This is mainly due to the newly developed industrial enterprises and the buildings. From the point of view of power supply and distribution, the small capacity of the power distribution transformer is generally not over 1250KVA, the power supply is stable for a long time, and the high voltage is open. Do not operate frequently.

Internal structure of environmental gas cabinet:

The 1. loop network cabinet is composed of four parts: switch room, fuse chamber, actuator room and cable room.

The 2. switch chamber is composed of busbars sealed by various functional loops in the metal shell and the circuits between them. The shell is welded by 3 cold rolled steel plates. Each functional loop consists of a load switch and a ground switch.

The 3. load switch adopts the air pressure internal blow type structure, which has strong arc extinguishing ability and does not affect the interphase and ground insulation. Both the dynamic and static contacts have arc contacts, which greatly improves the breaking times.

The 4. fuse and the load switch room constitute the transformer protection circuit, and the high voltage current limiting fuse is installed in the insulating shell of epoxy pouring. After the fuse breaks, the fuse is ejected and the load switch is cut.

The 5. operating mechanism room is located on the front of the ring net cabinet. In each function loop, the load switch is equipped with a human (or electric) spring operating mechanism. The grounding switch is equipped with a human energy storage spring operating mechanism. There are separate and closing operation holes for the switching operation of the load switch and the manual switch and the grounding switch on the panel. Load switch, switch position indicator light and electric division, switch button, and have analog line, switch state display card and lock position, load switch and grounding switch operation with interlocking device, in order to prevent misoperation.

Ring type cabinet type:

The HXGN-10 type cabinet structure is made of steel plate bending and welding, and the protection level is IP2X. The upper part of the cabinet is a bus room, the instrument room is located in the front part of the bus room, and is separated by steel plates. The middle part of the cabinet is a load switch chamber, and there is an insulating partition between the load switch and other components. For the cable inlet and outlet cabinets, there are removable movable covers at the bottom of the cabinets. For the overhead and outgoing cabinets, busbar passageways or sheltering shelves can be installed on the top of the cabinets.

The shell of HXGN-10 series ring net cabinet is made of steel plate bent and screw tightly assembled to form a metal enclosed structure. The cabinet is made up of 4 columns, upper cover plate, bottom plate, front panel, back panel and side panel. On the front side of the load switch cabinet, there are two doors with screws fixed on top, and 3 doors on the front of the fuse switch cabinet. There is an observation window on the door to observe the position of the load switch and the grounding switch; the busbar connection between the cabinet and the cabinet is the form of the plum blossom touch, and the busbar is equipped with an insulating sleeve.

The operating relationship between them is as follows:

(1) after the grounding switch is closed, the load switch can not operate and the positive panel can be opened.

(2) after the grounding switch is switched off, the load switch can be operated and the positive panel can not be opened.

(3) after the load switch is switched off, the earthing switch can be operated and the positive panel can be opened.

(4) after the load switch is closed, the earthing switch can not operate and the positive panel can not be opened.