Gas-filled cabinet C-GIS is the abbreviation of gas-insulated switchgear, which is defined according to the form of main switch insulation, corresponding to air-insulated switchgear and solid-insulated switchgear.
That is, the switchgear of the switchgear cabinet, circuit breakers and connections and other main circuits are sealed inside the gas box filled with insulating gas, the external main busbar, cable connections, etc. using solid insulation, the current transformer is mounted directly on the outlet casing or cable using a penetrating type, but also epoxy strut-type current transformers are mounted inside the gas box, and the terminals are reserved on the outside of the gas box. The voltage transformer is connected to the conical casing plug plate inside the gas box through the American cable head. High-voltage main and auxiliary circuits are not exposed in the natural air.
Ring network cabinet RMU is defined according to the application, the ring network power supply that is hand in hand power supply mode, also called the secondary power distribution equipment, a typical ring network cabinet through the two load switch as a ring in, ring out as a hand in hand power supply connecting equipment, with the load switch cabinet supporting the load switch fuse combinations or circuit breakers as a transformer outgoing switch, for the 1250 kVA and the following transformers, load switch fuse combinations are the most economical and effective protection of the transformer, and the load switch is a good choice. For transformers of 1250 kVA and below, the load switch fuse combination is the most economical and effective protection program. Transformers larger than 1250 kVA are switched by circuit breakers.
Ring mains cabinets are accompanied by voltage transformer cabinets to provide the operating power supply, metering cabinets for high voltage meters to be used for electricity metering, and direct feeder cabinets to be used as lead units.
The current of the ring network cabinet is generally 630A, short circuit breaking current 20kA, is a kind of small current switchgear. Air-insulated center-mounted switchgear can also be used for ring network applications, except that the air-insulated switchgear is larger in size, whereas the ring network cabinet is a compact switchgear specially designed for ring network applications. Early on, the ring network cabinet was a common box-type oil-insulated or gas-insulated switchgear, integrally integrated with the transformer, with small dimensions and light weight.
The current ring network cabinet is commonly used in the form of compact inflatable cabinet, that is, this compact ring network cabinet is a kind of inflatable cabinet, in fact, there are air-insulated form of the ring network cabinet, semi-insulated form, the use of vacuum load switch air-insulated ring network cabinet, the use of SF6 air package insulation form of semi-insulated ring network cabinet, so can not say that the ring network cabinet is an inflatable cabinet.
In addition to urban power distribution applications, the ring network cabinet is also used for distributed power generation collector boost, for wind power generation, more than 8MW wind turbine current through the ring network cabinet collector to the step-up transformer.
The current inflatable cabinet mainly refers to the primary distribution switchgear, i.e. for main distribution, rated current 630-4000A, short time withstand current 25-50kA, relative to the air-insulated switchgear, inflatable cabinets dimensions are greatly reduced, not subject to environmental influences.C-GIS adopts fixed vacuum circuit breakers, bus-side triple-position switching, there are two forms of direct-acting and rotary types, direct-acting current is large, the electric field is uniform, suitable for high-voltage and high current, and is suitable for high voltage and high current. It is suitable for high voltage and high current inflatable cabinet application.
40.5kV inflatable cabinet commonly used sulfur hexafluoride gas SF6 insulation, SF6 is one of the six greenhouse gases to limit emissions, the potential temperature effect index is 23,900 times that of CO2, and the degree of atmospheric damage is huge, so to SF6 has become the top priority for the improvement of inflatable cabinets, the use of dry air, nitrogen, and other gases can be used to insulate to avoid SF6 gas hazards.
Environmentally friendly gas insulated inflatable cabinet by using environmentally friendly gas insulation, sealed inside the gas box, not affected by the environment, small size, long service life, is the direction of the development of switchgear. Ring network cabinet distribution flexible, miniaturized intelligent, deep load center, conducive to distribution automation.