• Title/Summary/Keyword: Grounding conductor

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Effective Installations Technique of Grounding Conductors for Metal Oxide Surge Arrestors (배전피뢰기용 접지도선의 효과적인 설치기법)

  • Lee, Bok-Hui;Gang, Seong-Man;Yu, In-Seon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.6
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    • pp.253-259
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    • 2002
  • This paper deals with the effects of grounding conductors for metal oxide surge arresters. When surge arresters are improperly installed, the results can cause costly damage of electrical equipments. In particular, the route of surge arrester connection is very important because bends and links of leads increase the impedances to lightning surges and tend to nullify the effectiveness of a grounding conductor. Therefore, there is a need to know how effective installation of lightning surge arresters is made in order to control voltage and to absorb energy at high lightning currents. The effectiveness of a grounding conductor and 18 [㎸] metal oxide distribution line arresters was experimentally investigated under the lightning and oscillatory impulse voltages. Thus, the results are as follows; (1) The induced voltage of a grounding conductor is drastically not affected by length of a connecting line, but it is very sensitive to types of grounding conductor. (2) The coaxial cable having a low characteristic impedance is suitable as a grounding conductor. (3) It is also clear from these results that bonding the metal raceway enclosing the grounding conductor to the grounding electrode is very effective because of skin effect. (4) The induced voltages of grounding conductors for the oscillatory impulse voltages are approximately twice as large as those for the lightning impulse voltages.

An Algebraic Function Control on the Optimal Spaced Grounding Conductor (최적 접지도체간격에 관한 대수함수제어)

  • Song, Young-Joo;Choi, Hong-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.5
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    • pp.116-124
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    • 2006
  • No matter how the equally spaced grounding grid is designed there are many problem. The best-fitted design for unequally spaced grounding grid is a part that must be considered. This paper Suggest a new way of calculation for grounding grid space of ground conductor by an algebraic function control(The first-order function, Root function, Polynomial function etc.) and on the optimal spaced grounding conductor that make the under 2[%] between maximum potential and minimum potential.

The Numerical Formula Control Modeling Regarding on the Grounding Conductor Size Selecting (접지도체 굵기 산정에 관한 수식제어 모델링)

  • Song, Young-Joo;Choi, Hong-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.4
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    • pp.107-116
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    • 2006
  • The international standard to determine grounding conductor size can be applied for a wide range of items because it includes the specific physical characteristics, but it has a problem where the numerical formula is complicated. However the JIS and domestic standard numerical formula are simple but have many constraints. The new grounding conductor size selecting method is necessary in order to solve such problems. Therefore, in this study, we suggested an improved method for selecting the grounding conductor size and simple numerical formula with a numerical formula control modeling. and we verified reliability of paper used case study.

Effects of Length of Down Conductor on Transient Ground Impedance (인하도선 길이에 따른 과도접지임피던스 특성)

  • Lee, B.H.;Jeong, D.C.;Lee, S.B.;Lee, T.H.;Jung, H.U.;Lee, K.S.;Lee, S.C.
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2235-2237
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    • 2005
  • This paper presents the transient impedance behaviors of grounding systems to lightning impulse current. The potential rise and effective impulse ground impedance of the test grounding electrodes were measured as a function of the rise time of impulse currents and lengths of down conductor. The transient ground impedances strongly depend on the configuration and size of grounding electrodes, the impulse current shapes and lengths of down conductor, and the inductance of reduce of grounding electrode inductance is an important factor to improve the transient ground impedance.

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Hazards and Solutions of Loss of the PEN Conductor in TN-C-S System (TN-C-S계통에서 PEN도체의 단선고장의 위험성 및 보호대책)

  • Lee, Bok-Hee;Lee, Kyu-Sun;Ahn, Chang-Hwan;Kim, Han-Su
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.8
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    • pp.113-120
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    • 2007
  • This paper presents the electric shock hazards and solutions of loss of the combined protective and neutral (PEN) conductor in TN-C-S system. In order to mitigate the touch voltage on exposed-conductive-parts in a break in the PEN conductor, the touch voltages on exposed-conductive-parts in a break in the PEN conductor were experimentally investigated as a function of the ground resistances of the source grounding electrode and customer's additional grounding electrode. As a result, the equipotential bonding is one of important requirements for installations supplied by TN-C-S system. A solution of mitigating the touch voltages on exposed-conductor-parts caused by a loss of the PEN conductor would be the installation of the additional grounding electrode at the customer's service entrance. The ground resistance of additional grounding electrode necessary to limit the touch voltage to a safety voltage of less than 50[V] depends on the load and circuit parameters. In addition, the undervoltage sensing devices oner affordable solutions to detect a loss of the PEN conductor in TN-C-S system.

An Improved Method for Mesh Grounding System Using Spaced Arrangement of Grounding Conductor (접지도체의 간격배치에 따른 개선된 접지설비 모델)

  • Song, Young-Joo;Choi, Hong-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.3
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    • pp.57-65
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    • 2005
  • No matter how well the equally spaced grounding grid is designed, there we questions keep rising, such as leakage of current from comer conductor, high voltage of touch voltage in comers of grid than in center, and high material cost for grounding grid. The best-fitted design for unequally spaced grounding grid is a part that must be considered. Explain advantages of unequally spaced grounding grid and lead formula by dividing the number of grid division, j, into 20, instead of 7. Then, present Dij, which is optimum rate for unequally spaced grounding grid and verify safety and economy of the unequally spaced grounding grid by computer simulation with a poly-nominal function form.

Assessment of Equipotential Bonding and Electrical Continuity in Buildings (건축물의 등전위 본딩 및 전기적 연속성 평가)

  • Gil, Hyoung-Jun;Kim, Dong-Woo;Kim, Dong-Ook;Lee, Ki-Yeon;Moon, Hyun-Wook;Kim, Hyang-Kon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.385-386
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    • 2009
  • This paper deals with assessment of equipotential bonding and electrical continuity in Buinding by investigation on the spot at construction site. The assessment was carried out for continuity of steelwork in reinforced concrete structure, bonding conductor, protective conductor. A new grounding system based on international standards includes unity grounding system, structure grounding utilizing steel reinforced concrete, equipotential bonding, use of surge protective device.

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A Novel Non-contact Measurement Method for the Detection of Current Flowing Through Concealed Conductors

  • Yang, Fan;Liu, Kai;Zhu, Liwei;Hu, Jiayuan;Wang, Xiaoyu;Shen, Xiaoming;Luo, Hanwu;Ammad, Jadoon
    • Journal of Magnetics
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    • v.22 no.1
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    • pp.43-48
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    • 2017
  • In order to detect the current flowing through concealed conductor, this paper proposes a new method based on derivative method. Firstly, this paper analyzes the main peak characteristic of the derivative function of magnetic field generated by a current-carrying conductor, and a relationship between the current flowing through the conductor and the main peak of the derivative function is obtained and applied to calculate the current. Then, the method is applied to detect the conductor current flowing through grounding grids of substations. Finally, the numerical experimental and field experiment verified the feasibility and accuracy of the method, and the computing results show that the method can effectively measure the conductor current of grounding grids with low error, and the error is within 5 %.

Impulse Response Characteristics of the Grounding Systems with respect to the Common-Connection Position in Power Utility System (수변전설비에서 접지시스템의 공결점의 위치에 따른 임펄스 응답특성)

  • Lee, B.H.;Eom, J.H.;Kim, S.W.;Shim, P.S.;Lee, S.C.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2149-2151
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    • 1999
  • This paper describes the impulse response characteristics of the grounding systems in power utility system. Several regulations regarding to electric power equipments, services and managements require that the groundings of class 1 ($E_1$) and class 2 ($E_2$) must be connected at the common point in grounding systems. In addition, the grounding for arrester ($E_{LA}$), which belongs to the grounding of class 1, should be connected at the same point. However, there is no method and position of common-connection at anywhere. In this work, when the impulse current was injected through the grounding conductor for arrester, the investigations measuring and analyzing potential rises induced at the common connection point and other grounding conductors were conducted. The experiments were carried out in the conditions of the grounding conductor of 25m long and the near or remote common connection from ground electrode. The lightning impulse current was applied so as to simulate the on-set of arrester due to lightning and/or switching surges.

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Transient Characteristics of GIS Grounding Systems by Lightning and Fault (초고압 GIS 접지시스템에서 낙뢰 및 고장에 의한 과도특성 해석)

  • Lee, Hyung-Soo;Shim, Keon-Bo;Kim, Jung-Hoon;Chung, Sang-Jin
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.77-79
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    • 1995
  • In performing lightning and fault studies in GISs, it is of great importance to accurately model the conductor network consisting of the grounding systems and overhead conductor structures. In particular, the overhead grounded pipe enclosures of the GIS should be appropriately modelled. In this paper, the overhead pipe enclosures of a 500 kV $SF_6$ breaker and substation grounding system are presented in detail. During a phase-to-ground fault, scalar potentials and electromagnetic fields are computed at different frequencies for various conductor network configurations is defined by varying the number of conductors used to represent the pipes at different frequencies are obtained. Such knowledge will be very useful in reducing computation time for a transient ground potential rise study which will be performed in the future.

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