• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.120-120
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• 2010

To detect the PD events, we have studied a fusion sensor, the UHF sensor and the single-walled carbon nanotube(SWNT) gas sensor. We are accustomed to the UHF sensor which have employed to detect the partial discharges in apparatus GIS-like. But the SWNT gas sense is a newly way proposed to detect the partial discharges. In this study, we monitored not only the changes of the electrical conductance of the SWNT sensors in responding to the PD events but also the signal of the UHF sensor at the same time with IEC 60270 standard method for reference on the partial discharge events.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1461-1466
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• 2014

GIS(Gas Insulated Switchgear) is important power apparatus which have strong dielectric strength, supply electric power and is a part of the power system. Most substation type is configured as GIS. Recently, because of continuous increasement of GIS demand resulted from high quality & big capacity of electric power, the necessity of the preventive & diagnosis system is being expanded gradually. GIS partial discharge occurred on the UHF band is detected effectively by the method to IEC 60270 that recommend to be able to detect the apparent minimum discharge, 5 pC. Additionally, the UHF sensor should be installed to detect PD signal if Partial discharge signal, 5 pC occur in every part of GIS. Currently PD diagnosis system applying UHF sensor for GIS with various voltage level like 154 kV, 345 kV, 765 kV have been operated. And it is necessary to measure and analyze insulation breakdown phenomenon of inside GIS exactly. In this paper, we proposed Fat-dipole patch UHF sensor that is developed and more sensitive, excellent wide-range characteristic than the exising UHF sensor. And we performed KERI (Korea Electrotechnology Research Institute) reference test, which showed the excellent result for the all tests.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.3
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• pp.409-413
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• 2014

GIS partial discharge that occurred in the UHF band signal is effectively detected by the method to IEC60270 5pc the apparent minimum discharge can be detected over the GIS arrangement of the sensor interior and exterior of the UHF in accordance with the optimized position signal by considering the damping ratio is selected so that the signals can be obtained to be mounted. 362kV, 800kV GIS is installed on the internal and external sensors are UHF band signal attenuation is set by measuring the reference value, but the operation, 170kV case 362kV, 800kV on the basis of the measurement data and to be installed and operated. When 170kV per 1Bay by installing the built-in sensor 1 for detecting a partial discharge signal, But, GIS signal attenuation is large in the case of an internal partial discharge signal is not detected in some cases. Where the attenuation is great UHF signal of the sensor by increasing the quantity of partial discharge signals were acquired to allow relocation. The greater the spacing between the sensor and the sensor is applied simplifies the installation and reduces the cost in terms of maintenance of appropriate optimal position is calculated to detect the partial discharge signal is needed. Thus 170kV GIS signal power attenuation of a partial discharge by measuring the UHF sensor, and by relocating the proper position is calculated in accordance with the sensor signal decay rate and minimize the error of omission in detecting a partial discharge signal was optimized.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1511-1512
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• 2006

In this paper, we measured PD signals from artificial surface defects and corona discharges under laboratory circumstances like the fields using both HFCT-sensor and UHF-sensor for MV grade XLPE cable with AMP, spectrum analyzer and oscilloscope. Also, detected signals were analyzed via PRPDA system in this paper. As a result, in this case of HFCT-sensor, the amount of background noise are larger than as compared to UHF-sensor. There is needed some hardware or software or software algorithm removing background noise effectively for diagnosis the underground power transmission cable in the case of HFCT-sensor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.47-52
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• 2008

In this paper partial discharge were simulated by conducted particle, a fine protrusion, surface discharge, which could be easy accumulated charge and concentrated electric field in the model GIS. In this times this paper measured and analyzed the radiated electromagnetic waves by using spectrum analyzer and antenna ($30{\sim}2,000[MHz]$ for measurement of EMI EMC in accordance with occurrence and propagation of partial discharge. In the basis of this results, a novel UHF(Ultra High Frequency) spherical sensor is presented. The measured impedance bandwidth of the proposed antenna is from 0.3[GHz] to 1.7[GHz]. Form results of this study, this antenna will be playing an important role for the sensor for insulation diagnosis system by UHF method of real site GIS and power equipment using $SF_6$ gas.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.2
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• pp.83-90
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• 2004

This paper describes investigations of the UHF(Ultra High Frequency) PD(Partial Discharge) measuring technology designed for monitoring of PD in high power apparatus. Based on the spiral antenna theory, the hole type sensor for GIS with metal flange spacer and injection type sensor for oil filled transformer are developed. The experimental results show measurement characteristics of the PD sensor for several artificial defects in gas-insulated system(GIS) and oil transformer. Moreover, we proposed the new $\phi$-f-q method for the purpose of condition assessment of high power apparatus.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.37-39
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• 2002

UHF method is very effective to diagnosis for partial discharge of GIS. In generally, inner UHF sensor can be attached on sheath cover of GIS under construction for periodic inspection. However, there is no inner UHF sensor for GIS of the domestic substation. We used the outer UHF sensor attached on spacer for GIS of existing substation. In this paper, we report the diagnosis result of partial discharge on 800kV GIS in domestic substation. From these results, we can find the quantity, reason and location of PD and certificate the performance of UHF method for partial discharge diagnosis of GIS.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1638-1640
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• 2003

In the recent years, UHF PD measuring technique for detecting partial discharges was proved the effective method for Gas Insulated Switchgear (GIS). However, in case of GIS with a metal flange around insulating spacer, UHF PD measurement using typical external UHF PD sensor is difficult. In this paper, a novel hole-type UHF PD sensor based on Archimedean spiral antenna theory has been proposed and realized. All spacers with metal flange have small hole in order to inject epoxy. Using the novel hole-type UHF PD sensor, it makes detection possible to PD signal that are emitted through the epoxy injection hole. Additionally, the measuring characteristic of UHF PD signals from several artificial defects in GIS and the novel ${\Phi}$-f-q pattern analysis technology are discussed.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2038-2039
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• 2007

In this work, a novel semi-internal type UHF PD sensor has been proposed and related investigations has been performed in order to detect the partial discharges that could be possibly produced at the insulation system of the gas insulated switchgear(GIS). This sensor was designed to mount on the CT terminal hole of GIS using the spiral antenna theory. Therefore this type sensor can be install on GIS during the power apparatus has been operation and better sensitivity compare to the commercial external type UHF PD sensor.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.363-372
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• 1997

We have developed the UHF CW/FM proximity sensor system. The UHF CW/FM Proximity Sensor is the system which recognizes the distance from the antenna to the target using the UHF band signal. To adjust sensing distance, we must change modulation frequency parameter or modulation index parameter. When we select the modulation frequency paramter for adjusting sensing distance, new modulation frequency generator and new band pass filter will be required. It is so inefficient that we choose modulation index parameters for adjusting sensing distance. In this paper, theoretical principles of the UHF CW/FM Proximity Sensor are analyzed and doppler signals for the distance from the antenna to the target are measured as the modulation index($\beta$) being changed. Three systems of which moduation indices are 38, 50, and 61 are made. We concluded that the sensing distance will decrease as the modulation index($\beta$) increases. It is in accord with the theory of this UHF CW/FM Proximity Sensor System.