The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Heat treatment is one of the most important processes in production of insulating material. This paper presents space charge behaviors in low density polyethylene (LDPE). The LDPE specimens used for space charge experiments were obtained by three different heat treatment processes. These LDPE specimens have different degree of crystallinity and grain sizes. The accumulation and dissipation of space...
With the development of new insulation materials, vegetable oil-the best substitute for mineral oil-has gradually been widely used in the liquid insulation of transformers. To investigate the influence of vegetable oil on the thermal aging rate of oil paper, Kraft paper impregnated with mineral oil and vegetable oil underwent thermally accelerated aging at three different temperatures. Degree Polymerization...
In order to improve the oxidation stability of a new insulation oil derived from mineral oil and natural ester, the composite antioxidant used in the oil which were 2,6-ditert-butyl-4-methylphenol (T501) and high-purity alkylation-alpha-naphthylamine (L06) have been selected by using high pressure differential scanning calorimetry (PDSC), and the best concentration of the composite antioxidant in...
Crystallization and inner stresses can influence electrical aging properties of insulating material. Heat treatment is one of the most important processes in production of insulating material. This paper presents the growing properties of electrical trees in low density polyethylene (LDPE). The LDPE specimens used for electrical tree experiments are obtained by four different heat treatment processes...
The cellulosic insulation used in electrical transformers were aged in mineral oil and natural ester respectively to investigate the influence of oil type on thermal ageing properties of oil-paper. The accelerated ageing test was developed at three different temperatures and degree polymerization (DP) of insulation paper was measured to indicate the ageing extent of paper. Furfural concentration CF...
In order to compare the characteristics of natural ester impregnated Kraft paper and thermally upgraded paper, sealed aging vessels containing copper, insulation paper (Kraft paper and thermally upgraded paper), and natural ester were aged at 90, 110, and 130degC about 400 days. The results show that both degree of polymerization (DP) and leveling-off degree of polymerization (LODP) for thermally...
The accelerated thermal experiments at 90degC, 110degC and 130degC are performed, using the samples that Kraft paper or thermally upgraded paper were immersed by mineral oil or nature ester. The results show that the leveling-off degree of polymerization (LODP) for ester-immersed paper insulation is higher than the one for mineral oil-immersed paper insulation, and the time of getting to the LODP...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.