Journal Article•
Performance influence of high temperature vulcanization silicone rubber by alternating current corona discharge
TL;DR: In this paper, the hydrophobicity and temporality loss of Hightemperature vulcanization silicone rubber (HTV-SR) exposed to needle-plate electrode corona discharge were investigated by using scanning electronic microscope (SEM) and fourier transform infrared spectrum conjunction with attenuated total reflection (ATR-FTIR).
Abstract: The hydrophobicity,hydrophobicity recovery at different temperature,mechanical and electrical performance of hightemperature vulcanization silicone rubber(HTV-SR) exposed to needle-plate electrode corona discharge were investigated,and the damage phenomenon and molecular structure change of silicone rubber by corona discharge were also studied by using scanning electronic microscope(SEM) and fourier transform infrared spectrum conjunction with attenuated total reflection(ATR-FTIR).The test results show that there is clearly hydrophobicity decreasing and temporality losing at the surface of HTV-SR after corona discharge,and it is unable to recovery to the initial level.The higher is the temperature,the faster is its hydrophobicity recovery velocity.The static contact angle increases with the increasing of corona aging time,corona discharge leads to a sharp reduce of volume resistivity and dielectric strength,the dielectric loss angle is growing fast.The main damage phenomen on of silicone rubber caused by corona discharge is the black dust corona ring on the surface,whose diameter increases on the surface at first and then turn to depth direction combined with electrical erosion.The relative content of Si—O—Si,Si—CH_3,C—H show downtrend with the increase of corona aging time.It is the representation that the tensile strength and hardness descend,the defect and hole on the surface increase.
Citations
More filters
01 Oct 2011
7 citations
24 Dec 2013
TL;DR: In this paper, surface roughness of composite insulators was suggested as the added parameter in hydrophobicity tests, which can lead the water drop to two kinds of states transitions and it can make sample static contact Angle changed up to 31% within 10 minutes, which will also cause the different results of two measurement methods.
Abstract: Pretreatment needs to be done before measuring the hydrophobicity of the composite insulators. However, the necessity of such pretreatment is questionable for operating composite insulators. Therefore, surface roughness of light pollution level, heavily pollution level, chalking and the impact of surface roughness on hydrophobicity characteristic (HC) was investigated in this paper. The paper does the research on the result indicated the surface roughness is one of main factor about the pretreatment effect on HC level and static contact angle. The pretreatment effect on HC level and static contact angle seemed to be very obvious and the percentage of static contact angle changed up to 15.3%, as the surface roughness was varied. The Ra and RSM of different pollution level shed percentage change up to 130% and 269%. While Ra and RSM of high surface roughness degree reach up to 3.242μm and 400μm, the hydrophobicity on the composite insulators lost permanent. The surface roughness can lead the water drop to two kinds of states transitions and it can make sample static contact Angle changed up to 31% within 10 minutes, which will also cause the different results of two measurement methods. Surface roughness of composite insulators was suggested as the added parameter in hydrophobicity tests.
7 citations
08 Oct 2013
TL;DR: Wang et al. as mentioned in this paper showed that adding way and the amount of the ferric oxide powder are changed in the specimen-making process, and the influence of the colorant on the specimen's property under hot air environment has been discussed.
Abstract: The sheath and the shed in China are made of high temperature vulcanized (HTV) silicone rubber. The ferric oxide powder is widely used as red colorant, and it cannot disperse uniformly in the rubber for the reason that the ferric oxide powder is inorganic. In the paper, adding way and the amount of the ferric oxide powder are changed in the specimen-making process. Through hot air aging test, the changes of the specimen's electrical performances, mechanical properties and microstructure are considered, so the influence of the colorant on the specimen's property under hot air environment has been discussed. The results show that color masterbatch which is made of ferric oxide in advance, added in the rubber mixing process can improve the dispersion of the ferric oxide in the rubber, so that the ferric oxide can help reduce degradation of performance due to thermal-oxidative-aging. The radicals which are produced in silicone rubber's aging process could be trapped by the iron ions, which can be oxidated by oxygen in the air soon, and the amount of iron ions are not changed before and after the reaction. Therefore, increasing the content of iron oxide has no significant effect to improve the heat aging performance of the silicone rubber.
2 citations
Cites background from "Performance influence of high tempe..."
...INTRODUCTION Composite insulators mainly consist of glass fiber core, sheds, sheath and metal fittings, and they are widely used in the power grid because of their lightweight, good capability of antipollution and convenient maintenance compared with porcelain or glass insulators [1-4]....
[...]
...2008 [2] WANG Jianguo, “Performance Influnence of High Temeperature Vulcanization Silicone Rubber by Alternating Current Corona Discharge,” Acta Polymerica Sinica, 2009(4)....
[...]
...This is due to pyrolysis and oxidative cleavage occur in the molecular chain at a high temperature, and these reactions lead to the changes of molecular structure parameters, such as the value and the distribution of the average molecular weight, and this may lead to the induration of silicone rubber [2]....
[...]
TL;DR: In this article, the Fourier transform infrared spectroscopy (FTIR) of the sample was tested and the method of peak area was used to analyze the aging level of composite insulators.
Abstract: In this paper, the samples were cut from the composite insulator sheds, which have been running for about 10 years at different operating voltage of 110kV, 220kV and 500kV. The sheds include the high-voltage end sheds, low-voltage end sheds and the middle sheds of the composite insulators. The Fourier transform infrared spectroscopy (FTIR) of the sample was tested and the method of peak area was used to analyze the aging level. The results show that the aging of shed occurs mainly in the outer surface of the shed. The surface analysis of the shed shows that, three insulators of different voltage level have a same law, the aging degree in the composite insulator high-voltage side is most serious, followed by low-voltage side, and the aging degree is weakest in the middle part, and such law is even more obvious as the voltage level increases.
Cites methods from "Performance influence of high tempe..."
...For example, X-ray photoelectron spectroscopy (XPS) can be used to quantitatively measure composite insulator surface element contents; scanning electron microscopy (SEM) can be used to directly observe the large particles, pollution, empty, cracks and surface roughness of composite insulator surface; Fourier transform infrared spectroscopy(FTIR) can be used for analyzing the molecular structure[5-7]....
[...]