The breakdown property of oil-impregnated paper is a key factor for converter transformer design and operation, but it is not well understood. In this paper, breakdown voltages of oil-impregnated paper were measured at different temperatures. The results showed that with the increase of temperature, electrical, electro-thermal and thermal breakdown occurred successively. An electro-thermal brea...

In this paper, visualization and neural network techniques are applied together to a power transformer condition monitoring system. Through visualizing the data from the chromatogram of oil-dissolved gases by 2-D and/or 3-D graphs, the potential failures of the power transformers become easy to be identified. Through employing some specific neural network techniques, the data from the chromatog...

Background: In this research, the decomposition of Aroclor 1254, including 20 kinds of poly chlorinated biphenyls (PCBs), in real waste transformer oil in the presence of PEG1000, NaOH, zero valent iron and H2O by microwave (MW) irradiation was studied. Methods: Central composites design (CCD) method was carried out for experimental design. The effects of microwave power levels (200- 1000 W), ...

Heavy high viscosity oils, transformer oils, and very light low viscosity oils have been used in a Norwegian company in the impregnation, sheathing, and installation of paper insulated cables. The aim of the present study was to determine exposures to oils and other chemicals at these workplaces from 1920 to 1979. Oil mist was sampled on glass fibre or membrane filters and analysed by infrared ...

AN OPTIC FIBER SENSOR FOR PARTIAL DISCHARGE ACOUSTIC DETECTION by Xiaodong Wang Partial discharge (PD) is a very common problem in operating power transformers and is one of the factors that could lead to failure of power transformers, leading to power outage and expensive repairs. The acoustic wave induced by PD can be measured and used for monitoring, diagnosing, and locating potential failur...

power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. the resonant overvoltages may destroy the insulation between turns and cause to insul...

Present day power system is essentially a complex mesh of various important components with power transformer as one of the key elements. For the reliability of power supply, a robust maintenance tool for power-transformer is highly essential. To cater for this demand a portable, online diagnostic device is developed which can record the temperature and quantify the concentration of some of the...

background: poly chlorinated biphenyls (pcbs) are a class of chlorinated organic chemicals that do not easily degrade in the environment. this study was conducted to determine the effect of microwave rays, hydrogen peroxide, dioxide titanium and ethanol solvent on the degradation of pcbs. methods: a 900w domestic mw oven with a fixed frequency of 2450 mhz was used to provide mw irradiation. ray...