• 전기학회논문지
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• 제65권2호
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• pp.257-263
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• 2016

This paper describes the lightning arrester transients in cable head termination. The installation references of cable head tower and lightning arresters are firstly reviewed, then the performance of lightning arrester operation is also evaluated based on lightning overvoltage analysis by the change of grounding lead cable length. This paper finally proposes the optimal length of grounding lead cable at the cable head termination. The limited lightning current is also proposed according to the change of grounding lead cable length. The results will contribute to protecting insulation breakdown failure against lightning surge at the terminations and joints.

• 전기학회논문지
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• 제65권1호
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• pp.51-57
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• 2016

This paper presents the voltage characteristics of the various faults after lightning surge hits the overhead grounding wire close to the transformer's secondary side. Based on the modeled distribution system, the cases of the various faults occurred by lightning surge are simulated using EMTP/ATPDraw and maximum overvoltage and RMS voltage according to the distances from the transformer are investigated. As a result, it is seen that the voltage characteristics of faults caused by lightning surge is different depending on the fault type and the voltage characteristics can be used to detect the fault type caused by lightning surge.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권1호
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• pp.1-7
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• 2005

This paper describes the lightning surge analysis model of extra high voltage GIS using EMTP. Various lightning current parameters were investigated in order to confirm the impact on the lightning surge analysis such as lightning current amplitude, waveform, size of GIS, tower footing resistance and surge arresters. The multi-story tower model and EMTP/TACS model were introduced for the simulation of dynamic arc characteristics. The margin between the maximum overvoltage and BIL of the GIS was about 10 percent and the margin between the maximum overvoltage and BIL of the transformer was 21 percent.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.355-357
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• 2002

Distribution lines are spanned on a much large area as compared to transmission lines, and therefore, are more often susceptible to lightning strokes. The selection of the proper value of basic insulation level(BIL), for particular insolation components of distribution structures in specific, is very important. Lightning strikes has current risetimes ranging from 0.1 to several $\mu s$ and can produce transient overvoltages substantially greater than the BIL of many distribution systems in spite of lightning arresters. This paper describes lightning overvoltage of a 22.9kV distribution system due to lightning strike. This study will provide the information on insulation coordination studies to adopt BIL.

• 대한전기학회논문지:전력기술부문A
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• 제51권10호
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• pp.502-509
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• 2002

In the analysis of lightning surges, transmission towers are usually simulated by ATPDraw. The modeling of transmission towers is an essential part of the traveling wave analysis of lightning surges in transmission lines. The tower model is applied to the 154kV transmission tower of which surge performance characteristics are measured Tower surge response is computed using nonuniform, single-phase line models for both transmission tower and ground wire. The overvoltage will effect to the underground transmission line. The underground cable is combined by duct and trefoil type, and the each arrester is placed on the leading-in tube and outgoing tube. This paper analyzed the effect of lightning overvoltage on the underground cable system.

• 전기학회논문지
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• 제65권2호
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• pp.247-252
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• 2016

The latest offshore wind turbines are easily exposed to lightning strikes because they are designed with longer blades and taller height to satisfy the growing capacity demands. The generation facilities and elements of the offshore wind farm are more vulnerable to lightning damage because of more severe, unpredictable weather conditions. Therefore, this paper presents the analysis of measure for lightning overvoltage mitigation in offshore wind farm planned in South Korea southwest seashore. The sensitivity analysis includes the steady state and transient state characteristics of offshore wind farm and proposes the countermeasure for mitigation of transient overvoltage by considering earth resistivity of the offshore environment.

• 대한전기학회논문지:전력기술부문A
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• 제55권8호
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• pp.313-321
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• 2006

This paper describes the overvoltage obtained by surge behavior analysis in testing underground distribution systems. Model systems consist of overhead distribution line and underground cable. Such model system considered various characteristics of actual distribution systems will be soon constructed at testing yard. Simulation is carried out under various states such as cable kinds, cable length, lightning wave and time, and branch circuits. Model is established by EMTP/ATPDraw. Line Constants are calculated by ATP_LCC. When the direct lightning surge strikes on conductor of overhead line, the overvoltage is calculated using EMTP/ATPDraw in many cases. Simulation results will be compared with real testing results at testing yard in the near future. The compared results will be used to establish protection methods in actual underground distribution systems.

• 대한전기학회논문지:전력기술부문A
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• 제53권2호
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• pp.104-110
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• 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
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.491-493
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• 2001

This paper describes the effect of lightning current on combination transmission line. In the paper, an lightning current which can generate 2/80[${\mu}s$]. 20[kA] - 40[kA] waveform is modeled in ATPDraw. The lightning current invaded to the overhead power transmission line propagates to the underground power cable. The simulation was performed to analyze the effect of arrester location and overvoltage occurred in power cable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.561-563
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• 2003

This paper deals with simulation of lightning overvoltage generated by back flashover entering 345[kV] Gas Insulated Substation. In order to protect the substation equipment against lightning surge, insulation coordination is performed with the lightning arrester. This paper suggests optimal location of lightning arrester using the EMTP/ATPDraw to mere economically and effectively reduce the lightning surge incoming overhead lines.