Effect of calcium oxide on the electrical-insulation properties of electrical engineering periclase

Refractories ◽  
1989 ◽  
Vol 30 (3-4) ◽  
pp. 199-202
Author(s):  
T. V. Chusovitina
Author(s):  
El Hadi Belhiteche ◽  
Sébastien Rondot ◽  
Mustapha Moudoud ◽  
Philippe Dony ◽  
Omar Jbara

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 592 ◽  
Author(s):  
Xin-Dong Zhao ◽  
Wei-Feng Sun ◽  
Hong Zhao

Modified crosslinked polyethylene (XLPE) with appreciably enhanced DC electrical insulation properties has been developed by chemical modification of grafting chloroacetic acid allyl ester (CAAE), exploring the trapping mechanism of charge transport inhibition. The bound state traps deriving from grafted molecule are analyzed by first-principles calculations, in combination with the electrical DC conductivity and dielectric breakdown strength experiments to study the underlying mechanism of improving the electrical insulation properties. In contrast to pure XLPE, the XLPE-graft-CAAE represents significantly suppressed space charge accumulation, increased breakdown strength, and reduced conductivity. The substantial deep traps are generated in XLPE-graft-CAAE molecules by polar group of grafted CAAE and accordingly decrease charge mobility and raise charge injection barrier, consequently suppressing space charge accumulation and charge carrier transport. The well agreement of experiments and quantum mechanics calculations suggests a prospective material modification strategy for achieving high-voltage polymer dielectric materials without nanotechnology difficulties as for nanodielectrics.


1993 ◽  
Vol 32 (Part 1, No. 8) ◽  
pp. 3342-3345
Author(s):  
Yoohei Otoki ◽  
Masatoshi Watanabe ◽  
Susumu Takahashi ◽  
Shoji Kuma ◽  
Seiichi Okubo

2014 ◽  
Vol 87 (2) ◽  
pp. 360-369 ◽  
Author(s):  
Junping Zheng ◽  
Jin Tan ◽  
Hong Gao ◽  
Chuanzeng Wang ◽  
Zhilei Dong

ABSTRACT To satisfy some special demands of many applications in the fields of aerospace and the electronic industry, low temperature resistant and high electrical insulation chloroprene rubber (CR) was prepared by blending pristine CR with different weight ratios of butadiene rubber (BR). The low temperature resistance, electrical insulation properties, and mechanical properties of CR/BR blends were investigated. With increasing BR content, the low temperature resistance and electrical insulation properties were improved, whereas the tensile strength and elongation at break decreased. For the CR/BR (65/35) blend, filled with SiO2, the brittleness temperature (Tb) was reduced to −61 °C and the high electrical insulation properties were obtained without sacrificing mechanical properties too much. The tan δ plots of CR/BR blends, investigated by dynamic mechanical analysis, also revealed that BR could reduce glass transition temperature (Tg) and improve low temperature resistance of CR. The phase contrast microscope images of CR/BR blends demonstrated that the phase structure of the blends changed with increasing BR content. Furthermore, the fracture surfaces of CR/BR blends, observed by scanning electron microscopy, showed that the compatibility of CR/BR blends was poor although the CR/BR blends were homogeneous in macrostructure.


2019 ◽  
Vol 29 (2) ◽  
pp. 1-6 ◽  
Author(s):  
Shaotao Dai ◽  
Teng Zhang ◽  
Siming Mo ◽  
Yuan Cai ◽  
Wen Yuan ◽  
...  

2013 ◽  
Vol 64 (4) ◽  
Author(s):  
N. A. M. Jamail ◽  
M. A. M. Piah ◽  
N. A. Muhamad ◽  
R. A. Zainir ◽  
N. F. Kasri ◽  
...  

Polymer nanocomposites materials have recently emerged as a dielectric and for electrical insulation.  Polyethylene has long been used as extruded cable and HV insulation. Currently, this material has received significant attention because of its ability to enhance electrical insulation properties by addition of nano-filler. Polarization and Depolarization Current (PDC) measurement is an efficient and effective diagnostic technique based on time domain measurement for evaluating and condition monitoring of polymer nanocomopsite for HV insulation. Electrical conduction for polymer nanocomposites has been used widely as a tool to monitor the dielectric behaviour. This paper focuses on application of Polarization and Depolarization Current (PDC) testing method to evaluate and determine the performance of LLDPE nanocomposite for high voltage insulating material. The experiment was conducted to find PDC pattern of the material when added with nano-filler (silicon oxide) as well as to find its conductivity values at different percentage of nano- filler. PDC values and DC conductivity exhibits significant reduction with addition of nano-filler at different %wt of concentration. This was due to the decrease of initiation probability of short circuit treeing in the insulation. The PDC result shows that addition with certain percentage of nano-filler into the LLDPE based material could improve HV insulation properties of the material.


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