• 항공우주시스템공학회지
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• 제17권6호
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• pp.35-45
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• 2023

본 논문에서는 항공기용 차폐 케이블의 구조에 따른 간접낙뢰의 영향성을 분석하고, 차폐력 향상을 위한 차폐 케이블 구조를 분석하였다. 항공기에서 케이블은 부품 중에 가장 많은 비중을 차지하고 있고, 항공기 프레임과 전자기기들이 연결되어 있어 영향을 많이 줄 수 있다. 특히, 간접낙뢰 노이즈는 항공 전자기기 오동작 및 손상을 발생시킬 수 있어, 차폐 케이블을 활용하여 간접낙뢰 노이즈로 인한 피해를 줄일 수 있다. 항공기용 차폐 케이블의 차폐층 유무, 내심, 절연체 등의 케이블 구조에 따른 간접낙뢰 영향성 분석을 진행하였다. 또한, 간접낙뢰 공인 규격인 RTCA DO-160G Sec. 22를 적용하여 시뮬레이션 및 실험하여 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1734-1736
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• 1997

Insulator strings can be frequently damaged by fault currents occured by lightning strokes, overvoltages and contamination of the insulators. So the Insulator damages may lead to extensive damages to transmission lines as well as power outages that have caused dangerous situations to occur. This paper suggests the characteristics of arcing horn in relation to the protection of insulators and basic design concepts of the arcing horn for transmission lines.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.89-94
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• 2013

This paper presents a method of simulating the protection effects of surge protective devices(SPDs) depending on the protective distance and types of input impedance of load to be protected. In order to analyze the protective performances of voltage-limiting type SPDs associated with the reflection and oscillation phenomena, the terminal voltage across load being protected and the residual voltage of SPDs were simulated by using EMTP model as functions of the protective distance and types of input impedance of loads. As a consequence, SPDs should be installed by taking into account the protective distance and input impedance of loads to achieve reliable protection of electrical and electronic equipment from lightning and switching surges. It is expected that the simulation method proposed in this paper could be practically used in design for installing SPDs in low-voltage distribution systems.

• 한국안전학회지
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• 제31권6호
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• pp.19-24
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• 2016

One of key parameters on lightning protection system design of electric, information and communication system is grounding impedance. Earth impedance includes numerous information about earthing performance of grounding system. This paper suggests grounding impedance measuring device which is comprised of wideband current source, voltage and current measuring components. We used IQ Demodulation to measure more accurate phase difference of voltage and current. The range of frequency is up to 1 MHz that is IEEE defined as the range of lightning surge. We compared developed grounding impedance measuring device with existing one to test its performance, and we used grounding system while we implemented measurement and analysing by using fall of potential method IEEE Std.81 proposed.

• 한국초전도ㆍ저온공학회논문지
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• 제14권1호
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• pp.20-24
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• 2012

This paper proposes an insulation coordination and surge arrester design for superconducting power system with SFCL(Superconducting Fault Current Limiter) in Icheon substation. In the aspect of the economic analysis, since the superconducting devices are very expensive, the insulation coordination to prevent the dielectric breakdown caused by the lightning surge should be considered carefully. In this paper, the insulation coordination for real grid including SFCL and the design of the protection devices against lightning surge is verified using PSCAD/EM TDC.

• 조명전기설비학회논문지
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• 제29권3호
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• pp.81-87
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• 2015

In order to effectively protect electrical and electronic circuits which are extremely susceptible to lightning surges, multi-stage surge protection circuits are required. This paper presents the operational characteristics of the two-stage hybrid surge protection circuit in extra-low voltage DC power lines. The hybrid surge protective device consists of the gas discharge tube, transient voltage suppressor, and series inductor. The response characteristics of the proposed hybrid surge protective device to combination waves were investigated. As a result, the proposed two-stage surge protective device to combination wave provides the tight clamping level of less than 50V. The firing of the gas discharge tube to lightning surges depends on the de-coupling inductance and the rate-of-change of the current flowing through the transient voltage suppressor. The coordination between the upstream and downstream components of the hybrid surge protective device was satisfactorily achieved. The inductance of a de-coupler in surge protective circuits for low-voltage DC power lines, relative to a resistance, is sufficiently effective. The voltage drop and power loss due to the proposed surge protective device are ignored during normal operation of the systems.

• 조명전기설비학회논문지
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• 제28권9호
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• pp.52-59
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• 2014

The aims of this paper are to characterize the transient overvoltages(TOVs) and to evaluate the risk occurring at 22.9kV consumer's substation. The measurements of lightning- and switching-caused TOVs were made during Mar. 2013 and Feb. 2014. As a consequence, 47 events of TOVs were recorded and 4 of them were higher than the input voltage envelope(IVE) of the information technology industry council(ITI) curve. The measured TOVs are characterized by longer front times and longer durations compared to the $1.2/50{\mu}s$ standard impulse voltage waveform, and some of them represent bipolar waves with lower oscillation frequencies. It suggests that the test of non-standard impulse voltage waveforms is needed for effective risk assessments of power apparatus. Lightning- and switching-caused TOVs exceeding IVE of ITI curve are induced at the secondary of 22.9kV potential transformer(PT). We may, therefore, conclude that the surge protection devices should be applied at the secondary of PT and the surge absorbers should be installed at the primary of VCB or PT. The results presented in this paper could be useful to design the reasonable insulation coordination for 22.9kV consumer's substation.

• 전기학회논문지
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• 제63권12호
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• pp.1726-1731
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• 2014

This paper shows the developed new lightning arrester LCM (Leakage Current Measuring device) which is important element of GIS (Gas Insulated Switchgear) Preventive & Diagnostic system and verify its performance though strengthened test standards. The existing lightning arrester LCM was modified to solve measuring errors which happened frequently. At first, we explained the principle of measuring leakage current. Through analyzing some problems which the existing LCM have. we got some improvable items. For the performance verification of the improved LCM, we manufactured prototype LCM which is applied some improvable items such as improving LCM circuit, adding protection circuit, optimizing inner structure of LCM and changing ground design. After then we carried out the performance test. Accredited testing laboratory carried out the performance verification test according to performance test criteria and procedure of reliability test standards, IEC-60225, 61000 and 60068 etc. We confirmed the test results which correspond with the performance test criteria. Also, we confirmed the performance of the improved LCM installed & being operated at G Substation through the immunity test against the normal noise and open/close surge etc.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.70.2-70
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• 2001

This paper presents an application model for home automation control. In this work, we propose home application scenarios that are suitable for the home life style and design a control structure integrating various home automation functions, such as lightning, heating, cooling, security, fire protection, telemetering, entertainment and communication. State-of-the-art wired/wireless home networks such as Bluetooth, LonWorks, IEEE1394 and PLC(Power Line Communication) are included in the control structure.

• 조명전기설비학회논문지
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• 제27권2호
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• pp.54-61
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• 2013

This paper presents transient response behavior and frequency-dependent ground impedance of a single carbon ground electrode. The ground impedance of the carbon ground electrode was measured as a function of frequency of injected currents and simulated by using the distributed parameter circuit model with due regard to the frequency-dependent soil parameters, and the transient response behavior of the carbon ground electrode against impulse currents were investigated. As a consequence, the frequency-dependent ground impedance of the carbon ground electrode showed the capacitive behavior, that is, the ground impedance decreases with increasing the frequency of injected currents and lowers at the fast front time of impulse current. It was found that the carbon ground electrode is effective in grounding system for lightning protection. The ground impedance simulated with due regard to the frequency-dependent soil parameters was in good agreement with the measured data. The adequacy of the simulation technique and the distributed parameter circuit model for the carbon ground electrode was verified. It is expected that the simulation methodology, which analyzes the frequency-dependent ground impedance of the carbon ground electrode proposed in this work, can be used in the design of a grounding system for protection against lightning.