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Li H.,Xian Jiaotong University | Wang C.,Xian Jiaotong University | Guo Z.,Xian Jiaotong University | Wang H.,Xian Jiaotong University | And 3 more authors.
Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials | Year: 2015

Ultra high voltage (UHV) AC Gas Insulated Switchgear (GIS) spacer is one of the most important components in GIS. In the process of long-term operation, partial discharge often occurs at the interface between the center conductor and epoxy resin (EP) basin body if this interface has some defects, and the discharge sometimes even leads to the crack of basin. It has become a bottleneck for the safe and stable operation of GIS equipment. In this paper, the interface material with EP, hydroxy-terminated butadiene nitrile liquid rubber (HTBN) and conductive carbon black was created, and its parameters were measured. With three-dimensional finite element method, the interfacial structure with semi-conductive coatings were designed, the calculation models of GIS spacer which had interfacial layer structure were built. The influences of semi-conductive coatings on the electric field distribution of the interface between center conductor and basin body were studied. To different defects on the conductor surface, the improvement of the semi-conductive coatings to the electric field distribution was analyzed. Compared with the interfacial layer without coatings, there is an 80 percent decrease of electric field intensity of surface defects than that without coatings, which proves its significant shielding effect. The rationality of GIS spacer's performance of material and structure of semi-conductive coatings are verified, which is helpful to improve the uneven distribution of electric field at the interface of UHV electrical equipment. © 2015 IEEE.

A composite power transmission tower, and a composite cross arm structure of a composite tower for power grid transmission line is provided, including two sets of cross arm insulators arranged into a V-shaped arrangement horizontally, wherein a first end of each of the two sets of cross arm insulators is connected to the tower body of the composite tower at an opening of the V-shaped arrangement; and a set of oblique-pulling insulators, corresponding to each of the sets of cross arm insulators respectively, has one end connected to a second end of each of the two sets of cross arm insulators at an apex of the V-shaped arrangement, and the other end connected to the tower body over the two sets of cross arm insulators.

Kong W.-Z.,Jiangsu Shenma Electrical Co. | Fang J.,Jiangsu Shenma Electrical Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2013

To meet the need of miniaturization of HV switchgear, 145 kV SF6 gas insulated composite mini-bushing was taken as the design object, and a physical model of the whole bushing was built according to the requirements of the standard and engineering. The internal and external insulations of the mini-bushing were calculated, and its electric field was analyzed by the finite element method to determine the insulation structure. Test was conducted on the prototype, and the results indicate that the miniaturization design of the 145 kV SF6 gas insulated composite bushing is rational, and all performance indexes are satisfactory.

Li Z.,Jiangsu Shenma Electrical Co. | Xi X.,Jiangsu Shenma Electrical Co. | Xie C.,Jiangsu Shenma Electrical Co. | Sun Y.,Jiangsu Shenma Electrical Co. | Zhu Q.,Jiangsu Shenma Electrical Co.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2014

Large aluminum flange is manufactured commonly by sand mold casting for releasing and feeding difficulties. To improve product efficiency and quality, decrease surface roughness, a larger aluminum alloy flange with multi lightening holes was produced by metal mold low pressure casting, realizing continuous production. The 24 lightening blind holes in the aluminum alloy flange adopted iron-core fixture and dis-fixed core-pulling method. Wind-blowing for the metal mold was conducted to accelerate the cooling velocity. Through setting lower-cold iron, designing "reversen" gate and canceling ceramic sleeve as well as shortening feeding distance of riser and increasing solidification, feeding capacity of aluminum alloy flange was improved.

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