SF6 is a gas with excellent dielectric properties and is commonly used in gas-insulated equipment. However it has the high global warming potential. Thus, the development of new gases or gas mixtures for GIS, GIL is strongly desired. For dimensioning the gas insulated systems the support insulators (spacers) are of special interest. Contaminations on the insulator surface can cause field distor...

As Gas Insulated DC transmission systems unite the advantages of space saving installation and large transmission capacity this technology is increasingly discussed and investigated today. The main problem in operation with respect to insulation seems to be identified today, which is charge accumulation on the surface of the spacer. These trapped charges can cause a reduction of dielectric stre...

this paper proposes an optimal transmission expansion planning (tep) which is based on determining share of each line in merchandizing surplus (ms) of system, determining by independent system operator (iso). the more share of a line in ms of system denotes the priority of a line for expansion. the procedure of determining ms of each line in a power system is based on determining the ms share o...

OVERVIEW: Hitachi has developed smaller and more reliable gas-insulated switchgear (GIS) in response to demands for lower costs and stable power supplies. Reliability of this GIS was improved and the enclosure diameter was reduced in order to minimize the installation space by using new analysis techniques and rationalization in insulation design and in temperature rise criteria. Furthermore, t...

Gas insulated switchgear (GIS) plays an important role in the transmission and distribution of electric energy. Detecting and analyzing the decomposed components of SF₆ is one of the important methods to realize the on-line monitoring of GIS equipment. In this paper, considering the performance limits of intrinsic TiO₂ nanotube gas sensor, the adsorption process of H₂S, SO₂, SOF₂ and SO₂F₂ on f...

In this paper, an improved finite element (FE) model is proposed to investigate the temperature distribution in gas insulated transmission lines (GILs). The solution of joule losses in eddy current field analysis is indirectly coupled into fluid and thermal fields. As is different from the traditional methods, the surrounding air of the GIL is involved in the model to avoid constant convective ...

Chemical by product diagnostic technique is an efficient, cost-effective and reliable diagnostic technique for gas insulate switchgear condition monitoring in view of its high sensitivity and antiinternal and external electromagnetic interference and noise. In this research paper, coaxial simulated gas insulated switchgear chamber and four different types of artificial defect were designed to c...