• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.11
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• pp.1035-1042
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• 1998

After the 1990's, a computer-aided partial discharge(PD) measurement system was referred in part of aging diagnosis using digital signal processing as the new technology has been studied. The PD patterns and relevant information for pattern recognition are discussed in PD research area, because discharge quantity(q), the number of discharge pulse(n) and the applied boltage phase($\varphi$) was combined with the system information of the aging state. This paper investigates the discharge phase and quantity, as well as the number of discharge(n) with regard to discharge signals generated in power cable. therefore, according to characteristic analysis on the distribution of $\varphi$, q and n, it is able to apply in the aging analysis of power cable which visual observation is impossible and distribution change of discharge signals offers much information for risk degree on aging progress of insulation materials.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.12
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• pp.1269-1274
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• 2014

Since power and control cables have narrow bandwidth due to their loss at high frequencies, it is difficult to detect the weak fault using conventional reflectometry. It is because the reflected wave caused by the weak fault is overlapped and hidden by the ripple of the strong reflected wave from the end of the cable. This paper proves that the reflected wave from the weak fault can be considered to be linearly superposed on the strong reflected wave from the end of the cable based on the transmission line theory. Then, the weak fault point is experimentally diagnosed using the difference between reflection coefficients before and after the fault generation.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.1
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• pp.9-16
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• 2017

The performance test is conducted for the purpose of determining the accurate thermal performance of the power generation facility or deriving the factors of thermal efficiency degradation. Compared to the acquisition method of power plant thermal performance test data by compensating cable or transmission cable, performance test using wireless instrument can acquire digital data in order to shorten the period due to installation and demolition of instrument and enhance safety of workers and relatively accurate data can be acquired thereby improving work efficiency. Wireless instruments have already been introduced to the market a long time ago, and some of them are used in industry such as petrochemical industry. However, there is no example which has been conducted for performance test of power generation facilities. In order to apply power generation facilities, a reliable system capable of acquiring performance data smoothly without affecting the control system is required. The wireless measurement system can eliminate the measurement defects and errors such as the damage due to the movement of the connecting cable, the extension due to the extension of the shield wire, the contact failure at the contact point between the measuring sensor and the connecting wire, This method has the advantage of collecting relatively accurate performance test data.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1805-1807
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• 2004

This simulated partial discharge caused by 22.9[kV] power cable using XLPE(Peroxide Crosslinkable Polyethylene) insulation having the outside damage. Asone of the insulation diagnostic method a radiated electromagnetic waves were measured by an UHF method using a BiconiLog antenna(EMCO-3142) and a spectrum analyzer used to measure EMl, EMC. From results of this study, It was confirmed that discharge progress were possible to be estimated by the proposed method.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1353-1355
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• 1995

While the modern society has been highly diversified and civilized, the demand for the safty of a power transmission has been greatly increased. For the underground cable, the performance of the electrical equipments is being improved by developing a new technology, and the reliability of the power supply is being up graded by impressing the diagnostic and monitoring technology of the system. In this paper the aging procedure of O.F and XLPE cables are described, including the diagnostic and monitoring equipments and the future subject.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.122-126
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• 2002

A diagnostic test of 15.4kV cross-linked polyethylene(XLPE) ultra high voltage power cables from generator in the Soyanggang hydro electric power plant was conducted over 3 months, beginning April 2001. According to the results, in the case of the power cables from generator 1, there was little possibility of proceeding rapid1y to failure or defect because the data from diagnosis doesn't indicate any failure, deterioration or partial discharge. However, in the case of the power cables from generator 2, the. polarization index show a slight abnormal condition of the insulator that is not severe, and the deterioration was also identified as not severe. However, the partial discharge had an abnormal condition which was severe.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.153-154
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• 2006

We studied the improved detecting method on Partial Discharge occurred in EHV power cable. In this field, we usually applied the several sensor for partial discharge. This is metal foil employed with the capacity foil-sensor. We detected the partial discharge through regularly array standard foil-sensor for the better improvement of existed foil-sensor in this research. This test is progressed in real EHV liveline, we analyzed that compare existed foil-sensor to detect character of FSA(Foil Sensor Array) for this test. From this result, detective character of fabricated FSA showed better result than existed foil-sensor.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.777-782
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• 2005

In this paper, we designed and fabricated a partial discharge (PD) detector to diagnose the soundness of CNCV cables by analyzing PD pulses and to predict discharge locations. The PD detector is consisted of a coupling network with a discharge free capacitor and a detection impedance, a voltage follower and a low noise amplifier. Lower cut-off frequency of the detector is adjusted at 175kHz to block AC voltage and to pass discharge pulse only. The discharge location could be obtained by the time of arrival method using travelling wave propagation theory. In a laboratory test on an eighty meter CV cable, we could position the discharge location within a two meter error.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.43-47
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• 2016

This system is a diagnosis system that checks whether it causes a partial discharge of a power cable or not. It is to classify normal from abnormal-normal, PD (Partial Discharge) sound through analysis of RLCR (Relative Level Crossing Rate) and spectrogram energy algorithm. Partial discharge diagnostic system has a function that stores PD sound and analyzes the data. The wave shape of PD sound is similar to noise and is systematically generated by partial discharge. Therefore, in this paper, we could discreminate between normal and abnormal case using relative level crossing rate (RLCR) and spectrogram of frequency energy rate.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1410-1416
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• 2011

A corrosion detecting system for 22.9 kV distribution power line insulation cable, which can travel autonomously along the live line, is proposed. Eddy current test method is employed to detect the corrosion, and the system developed here is capable of detecting internal corrosion of a ACSR-OC. Somewhat details of the electrical and mechanical mechanism of the system and traveling algorithm are introduced. Experimental results applied to the sample cables having artificial corrosion and the operating distribution lines are provided. From the result, we confirmed that the system is useful for detecting internal corrosion of a ACSR, and is expected to be a new non-destructive testing equipment in the area of diagnosis for the distribution power line.