• 한국융합학회논문지
• /
• 제4권4호
• /
• pp.49-57
• /
• 2013

The lightning shielding of different 500 kV HVAC-TL high voltage AC transmission lines was analyzed. The studied transmission lines were horizontal flat single circuit and double circuit transmission lines. The lightning attractive areas were drawn around power conductors and shielding wires. To draw the attractive areas of the high voltage transmission lines, transmission line power conductors, shielding wires and lightning leader were modeled. Different parameters were considered such as lightningslope, ground slope and wind on lightning attractive areas. From the calculated results, the power conductors voltages affected on attractive areas around power conductors and shielding wires. For negative lightning leader, the attractive area around the transmission line power conductor increased around power conductors stressed by positives voltage and decreased around power conductors stressed by negative voltage. In spite of this, the attractivearea of the transmission line shielding wire increasedaround the shielding wire above the power conductor stressed by the positive voltage and decreased around the shielding wire above the power conductor stressed by negative voltage. The attractive areas around power conductors and shielding wires were affected by the surrounding conditions, such as lightning leader slope, ground slope. The AC voltage of the transmission lines made the shielding areas changing with time.

• 전기학회논문지
• /
• 제60권4호
• /
• pp.694-699
• /
• 2011

This paper compares the performance of lightning shielding analysis methods using the seven striking distance formulae in substation. For comparison, we evaluate the number of expected strikes and exposed area using WinIGS Software. Seven striking distance formulae are compared using the electrogeometric model analysis and the rolling sphere method. Based on the electrogeometric model analysis, the risk of shielding failure in either the whole substation or parts of it is determined. According to the simulation results, one can justify whether the substation satisfies the criterion of shielding design. In particular, according to the rolling sphere method, the exposed areas in substation determine the location of the additional shielding poles or shield wires. Therefore, the installation of the additional shielding poles and shield wires in substation was accepted by shield design at the phase conductors exposed in the larger area.

• 전기학회논문지P
• /
• 제59권2호
• /
• pp.191-196
• /
• 2010

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

• 대한전기학회논문지:전력기술부문A
• /
• 제50권8호
• /
• pp.359-364
• /
• 2001

This paper presents the influence of the lightning overvoltage and the shielding effect of lightning arresters and overhead grounding wires on the DC railroad systems. Modeling of railroad system is established in ATPDraw to perform the simulation and the line constants of railroad were calculated using ATP_LCC. When a direct lightning strikes to the DC railroad, the result of simulation reveals that the shielding effect of arresters is reduced at messenger, trolly-wire, and the shielding effects of overhead grounding wire is over 90% than the case which does not include it. Therefore it is evaluated that overhead grounding wires should be installed in the DC railroad line.

• 대한전기학회논문지:전력기술부문A
• /
• 제53권2호
• /
• pp.104-110
• /
• 2004

This paper describes the lightning overvoltage occurred differently according to installation methods of arresters and overhead grounding wire in case of double circuits distribution systems. First, the analysis models are established considering the severe case between upper and lower distribution line, when the direct lightning surge strikes to the overhead grounding wire. The lightning overvoltage is variously analyzed with the change of grounding interval and resistance, arrester installation interval as well as the magnitude of surge using EMTP. After simulation results are compared with the BIL which is now used at field, the authors propose the methods for suitable shielding in domestic distribution systems.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.280_281
• /
• 2009

The past 3 years study on the lightning faults data shows that the main reason is shielding failure rather than back flashover. Accordingly, we need to thoroughly consider about shielding failure angle of tower. Also, transmission line damage caused by shielding can be minimized if we avoid the steep slope area as a transmission line route.

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

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 춘계학술대회 논문집
• /
• pp.93-99
• /
• 2000

Using the EMTP(Electro Magnetic Transient Program) for the analysis of lightning direct voltage on the railway system, the shielding effects of overhead grounding wire on the railway were studied quantitatively. Installation of overhead ground wire and gap-type arrester such as s-horn Provides a 6.6㎸ HV distribution line with good protection effects. Even severe lightning induced voltage were create, 6.6㎸ HV lines can be withstand.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 E
• /
• pp.2080-2082
• /
• 1999

This paper describes the analysis results for the protection of lightning surge at 154 kV substation. We found that the surge arrester is needed at the inlet structure. The maximum overvoltage is 975 kV at the circuit breaker without the surge arrester at the inlet structure. This value can be lower than 600 kV by installing the surge arrestor at the inlet structure. In addition to the incoming surge from transmission line, the shield wire should be considered to prevent the shielding failure by the direct lightning stroke.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 E
• /
• pp.1843-1846
• /
• 1997

This paper describes the fault reducing effects of the 154 kV transmission tower by auxiliary grounding from the top of the tower to ground. The grounding surge impedance of the auxiliary grounding system is calculated by CDEGS(:Current Distribution Electromagnetic Interference Grounding and Soil Structure Analysis), and the critical lightning back flashover current and arcing horn dynamic characteristics are simulated by EMTP/TACS(:Electromagnetic Transient Program/Transient Analysis of Control Systems). The calculated results of total LFOR(Lightning Flashover Rate) shows that the LFOR can be reduced from 5.2(count/100km. year) to 3.4 by auxiliary grounding on the 154 kV transmission tower with one ground wire shielding system.