High voltage equipment

 Dead tank circuit breakers
 Gas-insulated switchgear

AO “Mirny atom” offers high voltage equipment produced by Japan AE Power Systems (Japan)
A necessity for new generating capacities rises significantly in view of the scientific-and-technical progress and the related growth of energy consumption. As a result, there is another necessity –delivery of electrical capacity to the customers. At this stage transmission and distribution mains systems are very important, but lately these networks have become more and more loaded and have heavy duty operation conditions. The solution is a usage of higher voltage, but this increases dimensions of the switchgears. The big sizes of the equipment increases a substation costs or sometime it is not possible at all. Gas-insulated switchgears provide for usage of higher voltage within limits of substation or building dimensions In addition, SF6 gas, used in GIS as an insulation medium, besides its dielectric properties has perfect surge suppression characteristics. Outdoor switchgears with the same number of connections and CBs will take 4 times more space in comparison with GIS. 
AO “Mirny atom” offers GIS produced by one of the leading corporation named Japan AE Power Systems (Japan) with nominal voltage from 110 up to 500kV. The offered GIS are designed according to the following diagrams: “single busbar”, “double busbar”, “ring type” and “3/2”. Nominal currents are up to 3150A for 110 and 220kV GIS and up to 4000A for 330 and 500kV GIS. The over pressure of SF6 gas contained in GIS is 0,6MPa; at this SF6 gas has better properties than transformer liquid. The equipment is designed in such a way that even in case of full loss of SF6 over pressure there is no insulation breakdown between conductors, and between the conductors and an enclosure.

GIS consists of circuit breakers, disconnect switches, high speed earthing switches, current and voltage transformers as well as cable, air and SF6 bushings. Puffer type CB with spring and hydraulic operation box provides for required operation time. GIS is completed in accordance with customer requirements. All equipment included in switchgear meets IEC and GOST standards. The equipment is manufactured and delivered to a site in the shortest possible time.
Also AO “Mirny atom” offers DT GCB produced by Japan AE Power Systems (Japan) with nominal voltage from 110 up to 500kV, nominal current 3150/4000A and breaking current up to 40/63kА. Upon special request we can offer SF6 DT CB with breaking current up to 80kA.  The construction includes a puffer type CB with spring and hydraulic operation box providing for required operation time. Internal current transformers provide for 0,2S accuracy class. Upon customer request, CB can be completed with porcelain and polymer insulators. 
The equipment meets IEC standards, and manufactured and delivered to a site in the shortest possible time.

DT CB has the following advantages in comparison with live tank circuit breakers: 
 

• Perfect seismic stability; High level of safety;
• Low impact of contamination on CB operation;
• Lower space for installation, as current transformers are integrated to DT CB;
• Low cost of installation, operation and maintenance. 

GIS:

Dead tank circuit breakers