• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1753-1755
• /
• 2003

MOF insulating cover used in 22.9 kV substation hasn't shown good performance in terms of electrical safety because of its defect by short clearance MOF cover and each input and output wire junction part. The MOF cover is easily moved by outside environment as wind or rain weather because of different size MOF cover and insulating busing, also can be leaded to breakdown by tracking. Therefore, we propose MOF cover which effectively prevents from electrical accidents in this paper. To decrease the electric field concentrated on specific part, we roundly design the shape of MOF cover and clearance between cover and live part was adjusted to be longer than before. The proposed MOF cover is evaluated by using the electric field solution program.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1413-1415
• /
• 2005

In paper, propose new partial resonance ZCS PWM controlled High frequency insulating Full-bridge DC/DC converter not using exciting current of high frequency transformer. It is compared with the existing principles in characteristics. It also realizes a widely stabilized ZVS operating using new On-Off control method at synchronized power rectification MOSFET of high frequency insulating transformer secondary. Finally, it is brought over 97[%] measurement -efficiency by proposed DC-DC converter. It is proved effectiveness of new methods using DC UPS PWM rectifier as switching power.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.3
• /
• pp.280-285
• /
• 2024

In this paper, the electrical properties of liquid insulating oil were analyzed by changing the ambient temperature change at 10℃ in-tervals from 0℃ to 30℃ through an insulation breakdown experiment in order to analyze the insulation performance of liquid in-sulating oil that varies according to temperature changes. As a result, it was confirmed through experiments that the lower the am-bient temperature, the higher the insulation breakdown voltage, depending on both the electrode shape and the electrode interval, and it was determined that the lower the ambient temperature, the higher the insulation performance of the liquid insulating oil.

• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1039-1041
• /
• 1995

This paper describes the performance of the widely used polymeric insulating material for outdoor insulation. Various methods to describe the surface aging of polymer materials such as the peak and average of the leakage current, the cumulative charge, the weight loss have been investigated. The relationship between surface current, time are plotted and discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.04a
• /
• pp.82-85
• /
• 1997

This paper describes the development of new type arrester for 22.9kV class distribution lines, with polymer insulating materials applied to their housings. The new arrester employs silicone insulating material for its housing, instead of the conventional porcelain housing, aiming at reduction in size and weight and explosion proof against internal short circuit failure. And, since the design of sheds is not restricted. it is possible to provide a long surface leakage distance per strike length and improve anti-contamination performance.

• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1436-1437
• /
• 1998

In this paper, the result of experimental investigation into the streaming electrification phenomena of insulating oil under an external dc field effect is described. Energization by positive dc voltage enhanced the streaming electrification. but when the applied voltage was negative, the polarity of streaming current was field strength dependent.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.4
• /
• pp.149-154
• /
• 2010

With soaring public concerns of environmental issues, many researchers have started to carry out research on various related topics in many areas of science and engineering. This paper describes a brief outline of typical recent research results obtained in the author's laboratory on electrical and optical properties of dielectric materials, done aiming at contributing to green power technology.

• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.190-191
• /
• 2006

In this paper, a method to assess the reliability of an insulating spacer used in gas insulated switchgear by electrical accelerated lifetime test is represented. And a test plan to assure the expected lifetime with 90 % confidence level is also included.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.34 no.12
• /
• pp.457-463
• /
• 1985

This paper studies on the tracking phenamena by the IEC recommended method with various polymeric insulating materials which are used in industrial fields. Under the same experimental condition, according to the materials it is observed that there are the type of tracking breakdown and the type of tracking erosion. In the tracking breakdown type materials, the tracking breakdown is occurred at a small number of drops increasing of test voltage and solution density. In the tracking erosion type materials, the erosion depth is saturated or proportioned as increasing of test voltage and solution density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1990.10a
• /
• pp.1-16
• /
• 1990

In this paper, a system to measure treeing degradation phenomena in organic insulating materials, using an image sensor, is discussed. Using an image processing technique, tree features immediately after tree initiation as well as changes in the configuration of the tree were measured. which up to now have been extremely difficult to observe by conventional visual methods. As a result, it was possible to record the image of tree propagation immediately after its first appearance, and to describe the specific characteristics of tree growth in terms of the length, the degraded area and the sequential images.