• 조명전기설비학회논문지
• /
• 제16권4호
• /
• pp.38-45
• /
• 2002

내본 논문에서는 뇌서지에 의해서 발생하는 컴퓨터를 비롯한 전자기기의 장해에 대한 보호대책을 제안하기 위해서내 국내의 뇌보호설비에 대한 규격과 지침에 대한 기술적인 문제점을 분석하였다. 인하도선의 설치방법에 따른 인하도선과 인입용 금속관을 통하여 흐르는 전류사이의 관계를 검토하였으며, 인하도선계에 미치는 표피효과의 영향을 평가하는 실험을 수행하였다. 그 결과 인하도선을 인입용 금속관에 전기적으로 접속한 때 인하도선과 금속관은 하나의 도체로 작용하며, 표피효과와 쵸킹효과 때문에 뇌격전류는 인하도선보다도 금속관을 통하여 훤씬 많은 전류가 흘렀다. 따라서 뇌격전류에 의한 인하도선의 전위상승으로 야기되는 정전유도와 측면방전 등의 악영향을 억제하기 위해서는 인하도선을 인입용 금속관과 건물의 철골 구조체에 전기적으로 접속하는 것이 매우 효과적이다.

• 조명전기설비학회논문지
• /
• 제25권9호
• /
• pp.94-99
• /
• 2011

This paper verified the characteristics of electrical continuity and mechanical strength of steelwork required to use it as a down-conductor in lightning protection system. It was proven that the steelwork in reinforced concrete apartment has an excellent electrical continuity with low resistance(less than 0.2[${\Omega}$].). But it was confirmed that a poor connection between two reinforcement bars can easily cause serious damages of the concrete even with the impulsive current of 50[kA], 10/350[${\mu}s$]. These results of experiments mean that the additional measures are necessary in using the steelwork as the down-conductor of the lightning protection system.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권2호
• /
• pp.109-115
• /
• 2004

This paper deals with the behaviors of magnetic flux density near down-conductors by lightning currents. The background on the principle of magnetic flux density measurements using the RL self-integrating magnetic field sensor was described. The magnetic flux density measuring device consisting of RL self-integrating magnetic field sensor and differential amplifier was designed and fabricated. The frequency bandwidth of the magnetic flux density measuring system ranges from 200 Hz to 300 KHz and the response sensitivity was 0.126 $\mu$T/㎷ The distributions of the magnetic flux density near down-conductors due to impulse currents with various rise times were analyzed as a parameter of the bonding conditions and materials of conductor and wiring conduits. The magnetic flux density due to impulse currents was inversely proportional to the distance between the down-conductor and measuring point. The amplitude of the magnetic flux density for PVC Pipe with down-conductor was 72 $\mu$T/㎷ at the distance of 1m and was higher than for steel conduits and coaxial cable. Finally the magnetic flux density is increased with increasing the di/dt it and oscillation frequency of lightning currents in this experimental ranges.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
• /
• pp.54-58
• /
• 2006

본 논문에서는 공동주택에 적합한 인하도선시스템과 접지시스템 설계를 위한 기본적 사항에 대하여 고찰하였다. 공동주택의 철근구조체는 전기적 연속성을 갖지만 철근들끼리의 결속선에 의한 접속은 전자기계력에 대한 내력이 부족하다. 따라서 전용의 인하도선을 설치하고 이들을 건물 양 측벽의 철근구조체와 본딩하여 낙뢰전류가 인하도선 및 철근구조체에 분산되어 흐르게 하는 인하도선시스템을 제시하였다. 한편 공동주택의 접지시스템은 건물기초접지극과 피뢰설비를 위한 환형 접지극으로 각각 구성하고 이들을 서로 본딩하는 접지시스템을 제시하였다. 또한 공동주택 각동의 건물기초접지극을 공동구의 철근구조체나 접지선을 이용하여 서로 연결함으로서 공동주택 단지에 거대한 총괄접지시스템을 구현하는 방안을 제시하였다. 하지만 이러한 피뢰시스템을 구축하기 위해서는 완벽한 본딩시스템의 구축이 전제되어야 한다.

• 조명전기설비학회논문지
• /
• 제16권4호
• /
• pp.8-14
• /
• 2002

현대의 뇌보호시스템은 낙뢰로 인한 감전이나 건축물, 전기·전자기기의 파손과 같은 위험성을 제거하는 것이 요구되지만 종래의 뇌보호설비는 단지 인명의 피해나 건축물을 보호하는 것이 주된 역할이었다. 오늘날 컴퓨터, 정보통신설비 등을 효과적으로 보호할 수 있는 뇌보호설비가 필수적 요건으로 대두되었다. 본 논문에서는 뇌과전압으로부터 컴퓨터와 전자장비를 보호할 수 있는 기술을 개발할 목적으로 인하도선의 종류와 설치기법에 따라서 인하도선에 유도되는 전위상승 억제에 대한 연구를 수행하였다. 그 결과 인하도선의 전위상승에 의한 측면방전과 위험성을 줄이기 위해서는 인하도선으로 낮은 특성임피던스를 가지는 동축케이블이 적당하며, 인하도선과 금속관을 상단과 하단에서 본딩하는 방법이 효과가 높게 나타났다.

• International Journal of Railway
• /
• 제3권2호
• /
• pp.46-53
• /
• 2010

Electric railroad systems consist of rolling stock, track, signal and catenary system. In the catenary system, one of the most important factors is the impedance according to the design and characteristic. Before the catenary system is designed, the impedance should be precedently researched. The railroad catenary system is complex system which is composed by five conductors. The five conductors classify up and down feeders, up and down contact wire group, rail group. Therefore, we should compose the catenary system of the equivalent five-conductors model. In this paper, we suggest a geometrical model and a equivalent conductor model by using geometric mean radius of five conductors in the catenary system. Also, we calculate demanded parameter values in the model. By using those, line constants of five conductors are analyzed by applying the equivalent method called as the condensed joint matrix.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 C
• /
• pp.1724-1726
• /
• 2001

This paper deals with the characteristics of the potential rises of down-conductor due to lightning surge currents. Direct lightning strikes can cause high impulse currents to the lightning protection system(LPS) of a building. These high impulse currents have the front time as short as 1[${\mu}s$]. In this case, the induced voltages caused in a closed circuit inside the building can be very high and cause damage or submit people to electric hazard. So, the LPS has to be designed to ensure safety condition to person and acceptable levels of induced voltages to the electrical and electronic equipments. The results of the potential rises related to the bonding conditions between the grounding conductor and metal raceway and the type of down-conductors are introduced.

• 조명전기설비학회논문지
• /
• 제27권7호
• /
• pp.101-107
• /
• 2013

IEC Standards on lightning protection system specify the use of natural components as down conductors. This paper provides an analysis of problems revealed from our field investigation and survey conducted for the relevant experts in the construction site where natural components are used as down conductors. It also considers a suitable condition for installing natural components as down conductors in accordance with the latest version of the standard. As a result, when rebars of reinforced concrete are used as down conductors, vertical bars consisting of rebars of which thickness is not less than D13($127mm^2$) should be connected by welding, clamps or bound joints, using appropriate connection components conforming to IEC Standards. The lashed joints, however, shall not be applied for down conductors.

• 대한기계학회논문집A
• /
• 제21권10호
• /
• pp.1730-1741
• /
• 1997

In this paper, we developed a surface profile measuring system and a profile measuring software for EGL conductor roll. For the profilemeter, we designed a linear guided control system with Laser displacement sensors and developed a 3-dimensional software. Additionally, the AC motor and AC motor driver were used to control the precise position of linear guide system. The measuring principle of the Laser sensor is optical triangulation method. Also, two Laser sensors were used to remove the disturbance and vibration effects of the linear guide system.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2005년도 학술대회 논문집
• /
• pp.125-127
• /
• 2005

This paper conducted to evaluate electrical continuity of steelworks within reinforced concrete apartment structures as the down conductor in external lightning protection system. The reinforcing bars in reinforced concrete structures can be used as the down conductor when their overall electrical resistance is not greater than the resistance value of 0.2 ohm between the uppermost part and the ground level. According to the results of electrical resistances measured by 4-terminal low resistance measurements, the steelworks in reinforced concretes structures exhibited the electrical continuity with low electrical resistance.