• 대한방사선기술학회지:방사선기술과학
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• 제9권1호
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• pp.73-81
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• 1986

This paper carried out an experiment on the characteristics of time, temperature, electric field and the dependense of electrode materials and gap length by the conduction current of the insulating oil used for x-ray tube housing. The obtained results can be summarized as following: 1. In the x-ray tube housing insulating oil with vacuum condition, conduction current is declined more than the x-ray tube housing insultaing oil with the air, and is held stable states. 2. At the low electric field the higher temperature of the x-ray tube housing insulating oil is increased, the more conduction current. 3. The dependence of electrode material is appeared at the low electric field and the short gap length than the high and the long with Fe> Cu >Al. 4. At the I-E characteristics, the low electric field than 1000 [V/cm] is appeared Ohm's law region, and the high become saturation region. 5. At the same electric field, the longer gap length become, the more conduction current is increased, and the same applied voltage, the longer, the less conduction current is decreased, the less low than high temperature x-ray tube housing insulating oil.

• 대한전기학회논문지
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• 제40권6호
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• pp.619-625
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• 1991

Phenomena of streaming electrification of insulting oil(T.O) is studied where the oil is contacted with solid insulating materials when it is pumped through a circulating system in a large power transformer. The leakage current, the electrical potential at the neutral terminal point of the transformer and the surface electrical potential of the oil are investigated. And the leakage current from the neutral terminal point is measured as a function of a bias polarity applied to a transformer case to investigate the polarty of ion which is absorbed in the case at the interface between the case and oil. As a result, it is found that insulating materials, and it is suggested that the leakage current is the sum of the relaxation current by positive charge from insulating oil to the neutral terminal point and by electrification current from negative charge electrified by the contact with solid insulating materials.

• E2M - 전기 전자와 첨단 소재
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• 제7권3호
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• pp.236-242
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• 1994

In this paper, the streaming electrification characteristics of insulating oil were examined when the oil is contacted with solid materials in a circulating system. The streaming current($I_s$) increases with increasing oil velocity and temperature, and electrification properties depend on species of metal materials. $I_s$ in the gauze-contained electrification apparatus increases with increasing oil temperature below the temperature of 43[>$^{\circ}C$], but decreases above 43[>$^{\circ}C$]. On the other hand, $I_s$ is positive electrificated for the pipe of Fe, Cu, while it is negative electrificated for Sus. When insulating oil flows through a car fuel filter, $I_s$ increases linearly with increasing oil temperature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1851-1853
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• 1996

In this paper the criteria for insulating oil condition of pole transformer were suggested by applying the UV-Visible spectrophotometric method. Ageing of insulating oil caused the change in absorbances of oil os well os the deterioration of electrical properties of oil. By comparing the electrical properties such as $tan{\delta}$ and breakdown voltage with the UV-Visible absorbances of oil, criteria for absorbance values determining oil condition were established. This UV-Visible spectrophotometric method might be applied in ageing analysis of oil and be expected to replace the current method.

• 한국조명전기설비학회지:조명전기설비
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• 제5권3호
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• pp.72-77
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• 1991

In a large power transformer, insulating oil is forced to circulate for cooling the heat generated by the losses within windings and core. When insulating oil flows and rubs against various materials, such as insulating paper or core, the electrostatic charges are separated at the interface of the oil and the solid material. This paper considers the streaming electrification of various materials used in the transformer. In this study, we show that a solid material such as paper is negatively charged. On the other hand, a solid material such as core is positively charged.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.155-158
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• 1999

Because the traditional filters have many demerits, multi-step electric oil filter have manufactured the efficiency of insulating oil to improve. Therefore, the function of oil filter to improve based on my experience and know-how about my job. Through this study have obtained many merits. The efficiency of insulating oil is improved. The waste oil reused in repair works of the damaged transformer. Multi-step filter is shortening the working time and safety. it is handy for use and movement. This study lengthen the expected life span of filter. The improvement of oil filter bring about elevation of productivity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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• pp.72-75
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• 1993

The characteristic of streaming electrification and static charge diminution in Cu, Fe and Sus pipes were investigated. The Cu and Fe pipes are charged positively, whereas the Sus pipes are charged negatively. Electrification rate in Cu and Fe pipes increases with increasing a pipe length for no-charged insulating oil. The electrification rate in Cu and Fe pipes abruptly increase with increasing the temperature and flow rate of insulating oil but decrease in Sus pipes. The current flows as a direction of insulating oil in all pipes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1534-1536
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• 1997

In this paper, the streaming electrification phenomena of insulating oil by metal filters and the charge elimination method were investigated. When BTA and surfactant is molten in insulating oil, BTA appear the prevention of electrification from about 5ppm and surfactant (SP-S10, SP-S30) appear the prevention of electrification from about 20ppm. BTA increase the conductivity of insulating oil but surfactant and antioxidant(DBPC) isn't affect that.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1079-1081
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• 1998

This paper describes the dissipation factor measuring device for insulating oil in operating pole transformer by DSP(digital signal processor). After applying voltage to the sensor which is installed in a transformer, acquire source voltage and current of sensor using FFT techniques, then we could evaluate the dissipation factor of insulating oil. To improve measuring accuracy and processing speed, we use TMS320C31 DSP, FFT and data analysis techniques. Also we suggest deterioration criterion of insulating oil and compared the developed diagnosis device with schering bridge on deteriorated insulating oil. The result of this paper show that the developed measuring device can be used as diagnosis device for the pole transformers.

• Tribology and Lubricants
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• 제35권3호
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• pp.151-157
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• 2019

Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, $CO_2$ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.