• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.259-261
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• 2003

This paper suggests wireless diagnosis and monitoring system using SMS mode of mobile communication network for distribution transformer which could prevent electrical accident in the near future. Data are acquired by measuring the temperature of insulator oil in the distribution transformer and load current. Data acquisition of sensor using mobile communication network carried out filtering of sensor's output to optimize the size of send data Merit of this inspection method is that management, control and monitoring some transformers can be carried out using only one server. This inspection method will be the way of inspection to be worth spotlight in the near future because it is able to solve easily with the minimum facility inspection about state of transformer which is operating, to wide coverage about machine's wrong operation in other field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.527-528
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• 2007

A field-oriented UHF system for on-line PD monitoring of transformers is designed, which has been installed inside the oil tank of a 220kV transformer in a substation. This system has successfully captured long intermittent discharge signals that hadn't been detected through conventional techniques, and solved the problem successfully. The results demonstrate that UHF technique has great advantages for on-line PD monitoring of transformers. By adopting the peak detection technique, it becomes easy and effective for the transplantation of the phase-resolved pattern recognition technique from conventional method to UHF method, and then to realize continuous on-line monitoring, source characterization and trending analysis.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.4
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• pp.93-102
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• 1995

The purpose of this paper is to analyze the streaming electrification mechanism (SEM) generated in UHV transformer. This experiment used Couette Charger and interpreted the mechanism hydromechanically and electromagnetically. This work estimated the turbulent core density ($\rho$o) by measuring the short circuit current (isc) and the open circuit voltage (νoc) generated in Couette Charger and also studied the changes of the short circuit (isc), the open circuit voltage (νoc), the turbulent core density ($\rho$o) and the conductivity ($\sigma$) with adding BTA to restrain streaming electrification. as a result adding BTA increased the conductivity of oil and decreased the turbulent core density($\rho$o).

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.417-421
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• 1996

A new concept of 22.9kV class revenue metering system based on the optical sensing technique was designed and implemented. This paper reports on the performance of a 22.9kV class three phase optical current/voltage metering scheme and three tariff metering system. This optoelectronic system was designed and developed to advance the state of the art in revenue metering. This paper deals with the characteristics of designed optical CPT (Current and Potential Transformer) and optoelectronic demand meter. The extensive field evaluation of the developed system with the existing oil filled transformer and solid state metering pair is undertaking. Upto now the operation of the optical revenue metering system under the field condition compares favorably with the existing system.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.61-63
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• 2000

As increasing the failure of distribution transformers, we need to manage them efficiently. This paper proposes the method for distribution transformer's management using loss-of-life calculation. The Data Acquisition System(DAS) was developed to manage transformers and the HDLC protocol applied to the system. It will be feasible application to diagnose distribution transformers by checking load conditions such as top oil temperature, ambient temperature, load current, etc. and using loss-of-life calculation.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.67-69
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• 1992

This paper presents the new protective device which is developed specifically for use in oil filled distribution transformers. This device is mounted Inside of the transformer and connected between the secondary winding and the secondary bushings. It provides both fault and overload protection to the transformer, and visual warning of the existence of uneconomical loading conditions. It Is available in thermal/magnetic operating device depending upon fault duty required.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1556-1558
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• 1996

In order to investigate the electrical properties for transformer oils which contains a pure sodium chloride, the dielectric properties is made researches. This experiments for measuring the dielectric loss is performed at $20{\sim}120[^{\circ}C]$ in the temperature range, $30{\sim}1.5{\times}10^5[Hz}$ in the frequency range and $300{\sim}1500[mV]$ in the voltage range. The result of experiment for the movement of carrier and the physical constants to contribute dielectric properties of specimen with a pure sodium chloride.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.4
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• pp.53-59
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• 1992

This paper describes an instrument for the detection and geometric location of partial discharge (PD) source in transformers. This instrument measures electric current pulses and ultrasonic pulses simultaneously, counts the number of electrical pulses and determines the geometric location of PD in transformers. It was found that there is a relationship between partial discharge magnitude and pulse repetition rate when the applied test voltage and oil temperature were varied. Through the laboratory test using model transformer, it was clarified that this detector could be used for detecting and locating PD in the transformer.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.279-282
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• 1990

This paper describes an nstrument for the detection and geometric location of partial discharge(PD) sources in transformers. This instrument measures electric current pulses and ultrasonic pulses simultaneously, counts the number of electrical pulse and determines the geometric location of PD in transformers. It was found that there is a relationship between partial discharge magnitude and pulse repetition rate when the applied test voltage and oil temperature were varied. Through the laboratory test using model transformer, it was clarified that this detector could be used, satisfactory for detecting and locating of PD in the transformer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.206-210
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• 1996

In order to investigate the electrical properties for transformer oils which contains a Pure sodium chloride, the dielectric properties is made researches. To measure the dielectric loss of specimen, a coaxial cylindrical liquid electrode is used, and its geometric capacitance is confirmed to 16[pF]. And the dielectric dissipation factor, tan$\delta$, is measured by using the Video Bridge 2150. The thermal static oven with an automatically static temperature controller is used so as to support specific temperature to the specimen. This experiments for measuring the dielectric lass is performed at 20-120[$^{\circ}C$] in the temperature range, 30∼1.5x10$\^$5/[Hz] in the frequency range and 300∼1500[mV] in the voltage range. The result of experiment for the movement of carrier and the physical constants to contribute dielectric properties of specimen with a pure sodium chloride.