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The space charge characteristics of insulation paper are crucial under direct current. Thus, improving the space charge behavior of insulation paper is essential. In this study, a nanostructure AlOx film was coated on the surface of insulation paper via RF magnetron sputtering. The space charge distribution was measured using a pulsed electroacoustic instrument. After coating with nanostructure AlO...
Much work has been done to prevent copper corrosion in insulating oil with corrosive sulfur. Most of the research has focused on the addition of metal inhibitor and absorbent. Besides, changing the grain size and micro-structure of copper winding was an effective method to enhance the copper corrosion resistant. In this study, pure copper annealed at elevated temperature (400°C/20min) after cold rolled...
As transformer accidents occur frequently, one of the main reason for such accidents has been confirmed after the disassemble researches with the deterioration of oil-paper insulation caused by the existence of corrosive sulfide. Taking this situation into consideration, a volume of researches have been undertaken in this paper to understand the effect of different dibenzyl disulfide (DBDS) concentration...
In order to better apply time-domain dielectric response technique in non-destructive diagnosis of transformer's aging state, the influences of testing temperature on time-domain dielectric property of oil-paper insulation was investigated. Firstly, the experiments of oil-paper insulation winding model under different testing temperatures were carried out. After then, the integration of time-domain...
The power transformer is one of the important equipment for ensuring the safe and stable operation in the power system. Accurately assessing the ageing condition of oilpaper insulation in transformer is essential and important. Polarization and Depolarization Current (PDC) technique can sensitive to reflect the insulation condition of oil-paper insulation system. The PDC behavior of mineral oil-paper...
The oil-immersed power transformer is the core equipment for energy transmission and distribution power system. Assessing the condition of Oil-paper insulation system accurately is tremendously significant. Polarization and depolarization current measurement (PDC), which is based on the dielectric response, is currently widely used for condition assessment of transformer insulation as non-destructive...
In order to study the growth characteristics of electrical trees in XLPE cable under secondary pressuring, a short cable metal needle defect test device is adopted to study the growth characteristics of the new trees after the electrical trees in XLPE cable under the action of the voltage of 12 kV are influenced by secondary pressuring (15 kV). The research results show that influenced by secondary...
The life span of the transformer is mainly decided by its solid insulation, especially insulation paper (pressboard). In order to analyze the ageing mechanism of power transformer insulation paper, we use the atomic force microscope (AFM), which is one of the important instruments in nanometer area to observe the surface of thermal aging insulation paper. Through the comparison of some specimens'...
Automated mapping/facilities management/geographic information system (AM/FM/GIS), which provides a powerful way to process graphic and non-graphic information, can construct a spatial database system with topological structure and analysis function by combining diversified information in power system with geographic position-related graphic information. Based on the AM/FM/GIS and on-line monitoring...
This paper describes the theoretical analysis and experimental investigations of a differential loop and a Rogowski coil for measuring pulsed power with hundreds KA amplitude and tens NS rise time. According to the results of the investigation the differential loop and the Rogowski coil have been developed. The rise time for both impulse current measuring devices itself is about 1 ns. Both devices...
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