• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.23-29
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• 2005

This paper presents the characteristics of leakage currents flowing through ZinC Oxide(ZnO) surge arrester blocks under mixed direct and 60 Hz alternating voltages. A mixed voltage, in which an alternating voltage is superimposed upon a direct voltage, appears on the HVDC system network. The mixed direct and alternating voltage generator with a peak open-circuit of 10 kV was designed and fabricated. The leakage currents and V-I curves for the fine and used ZnO surge arrester blocks were measured as a function of the voltage ratio k, where the voltage ratio k is defined as the ratio of the peak of alternating voltage to the peak of the mixed voltages. The resistive component in the leakage current in the low conduction region is significantly increased with increasing the voltage ratio k. The V-I characteristic curves for the mixed voltages lies between the direct and alternating characteristics, and the cross-over phenomenon in the high conduction region was appeared.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.149-152
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• 2001

In this paper, aging diagnosis method of CV cable was investigated. CV cable was designed for the sake of using during 30 years. Therefore it was important to evaluate the cable's remaining life because CV cable used for power transmission line since 1970's. CV cable was mainly installed at the underground owing to the environmental condition. If the cable accident occurred, it needs the much time for the accident recovery and the much damage at the industrial activity. therefore, this paper should study the direct leakage current method, a sort of the cables' aging test method

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.149-152
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• 2001

In this paper, aging diagnosis method of CV cable was investigated. CV cable was designed for the sake of using during 30 years. Therefore it was important to evaluate the cable's remaining life because CV cable used for power transmission line since 1970's. CV cable was mainly installed at the underground owing to the environmental condition. If the cable accident occurred, it needs the much time for the accident recovery and the much damage at the industrial activity. therefore, this paper should study the direct leakage current method, a sort of the cables'aging test method.

• Journal of Power Electronics
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• v.16 no.1
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• pp.66-73
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• 2016

The quantity of alternating current (AC) leakage and the value of distortion factor in capacitor currents are discussed with regard to a new power component called variable capacitance device (VCD). This component has terminals for controlling its capacitance. Nonlinear dielectric characteristics are utilized in this device to vary the capacitance. When VCD operates in an AC circuit, the AC leakage from this device through direct current (DC) control voltage source increases according to the conditions of DC control voltage and so on. To solve this problem, we propose techniques for suppressing AC leakage. Although VCD has strong nonlinear characteristics, the current through the capacitor is not distorted significantly. The relations between AC leakage and the distortion in current waveforms are investigated. An application example for an AC power regulator is also introduced to evaluate the distortion in waveforms.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.377-384
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• 2009

In this paper, leakage current sensing module of SoC(System on Chip)type and real time monitoring system under consideration of electromagnetic interface in power trunk line are developed. The first, leakage current sensing module of SoC type under consideration of electromagnetic interface is developed, and the developed sensing module of SoC type is composed of leakage sensing part, power supply part, interface part, communication part, AD(Alternating current to Direct current)convert part and amplification part. And also the electromagnetic compatibility is evaluated by conduction and radiation of EMI(Electromagnetic Interference) for developed sensing module. The developed system can have confidence, stability and do energy saving under mixed electric circumstance of the low voltage communication device and high voltage equipment. The second, the real time remote monitoring system is developed using designed wire and wireless communication module with leakage current sensing module of SoC type. The developed real time remote monitoring system can monitor sensing state, occurrence state of leakage current and alarm for each step etc.. And the device configuration, PCB layout for leakage current sensing module of system on chip type and the experiment configuration in consideration of EMI are presented. Also the measurement results of conduction and radiation for EMI are presented.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.6
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• pp.566-572
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• 2004

It is necessary to measure the direct current with a non-contact methodology for the liquid or gas phase, as welt as the conducting metals. This paper described a theoretical consideration and experimental verification for a non-contact quantitative direct current measurement system using the Faraday effect and magnetic flux leakage. The leakage of magnetic flux occurs around a gap when a ferromagnetic core including the discontinuous gap is magnetized. Two large anisotropic domains in a magneto-optical film are occurred by the vertical component of leaked magnetic flux and the domain walls are paralleled to the center of the gap. Here, the symmetrical arrangement of domains are deflected when a vertical magnetic field is applied to the magneto-optical film. The domain wall of the magneto-optical film are relocated when a measuring current passes through the ferromagnetic core. Therefore, a direct current passing through the core can be determined quantitatively by the measurement of moving distance of the domain wall.

• Journal of the Korea Safety Management & Science
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• v.3 no.4
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• pp.45-52
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• 2001

In order to Investigate water tree degradation behavior on XLPE cable, direct voltage of 200 to 800V has been applied to the material at 5$0^{\circ}C$~10$0^{\circ}C$, and the water tree property has been correlated with voltage and temperature. The leakage current was increase as temperature increased and the Ohm's law was generally satisfied in this experiment though some experimental errors were found. The leakage current was decreased and reached to the stable state with time. It was also shown that the time for the stabilization of leakage current was lessened as voltage increased

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.223-225
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• 2016

The newly proposed analysis method using a direct-current current-voltage (DCIV) simulation is introduced for investigating leakage current composing MOS transistor. From comparing the density and location of traps using DCIV method and investigating the leakage current of gate channel transistor, we proposed the graphical analysis method to correlate the DCIV current and leakage mechanism by the traps. And, our graphical method intuitively explains that leakage current in MOS transistor is well correlated with the DCIV current of the MOS transistor arrays due to two kinds of traps created by Fowler-Nordheim (F-N) stress and Hot carrier stress, respectively.

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.423-428
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• 2003

In a direct modulated semiconductor laser diode. the structural dependence of current blocking layers was studied in view of the leakage current reduction and the bandwidth expansion. To analyze the leakage current and the parasitic effects, the current-voltage derivation characteristics and the subtraction method were used, respectively. It was shown that the‘inin’type current blocking structure might be the best choice for the purpose of the static and dynamic characteristics.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.111-117
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• 2009

This paper presents the characteristics of leakage currents flowing through zinc oxide (ZnO) surge arrester elements under the combined direct-current (DC) and 60 Hz alternating-current (AC) voltages. The current-voltage characteristic curves (I-V curves) of the commercial ZnO surge arrester elements were obtained as a function of the voltage ratio a. At constant peak value of the combined DC and AC voltage, the resistive leakage current of the ZnO blocks was significantly increased as the voltage ratio $\alpha$ increased. The I-V curves under the combined DC and AC voltages were placed between the pure DC and AC characteristics, and the cross-over phenomenon in both the I-V curves and R-V curves was observed at the low current region. The ZnO power dissipation for DC voltages was less than that for AC voltage in the pre-breakdown region and reversed at higher voltages.