Analysis Of Lightning Surge Phenomenon And Surge Arrester . - WSEAS
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSAnalysis of Lightning Surge Phenomenon and Surge ArresterPerformance of a 400kV Transmission SystemMD. SALAH UDDIN YUSUF, ABDUL MUNEM SAAD, MONIRA ISLAM, andCHOWDHURY AZIMUL HAQUEDepartment of Electrical and Electronic EngineeringKhulna University of Engineering & TechnologyKhulna- 9203BANGLADESHymdsalahu2@gmail.com munemsaad@yahoo.com, monira kuet08@yahoo.com, andc.azimulhaque@gmail.comAbstract: - Lightning causes abrupt interruption in electrical power network. In this study a 400kV transmissionsystem has been modelled to observe the influence of lightning surge current front time and tail time, backflashover phenomenon and performance of transmission line surge arresters. At first, induced voltage on the topof the tower has been observed for different front times and tail times of the same surge current function. Adynamic insulator flashover simulation model is also developed based on the voltage–time characteristics curveof the insulator string to observe the insulator flashover phenomenon. Effect of front time of the surge currenton insulator flashover has been observed for the mentioned two different cases such as direct strike on theoverhead ground wire and tower top of different surge currents and it has been found that insulator flashoverphenomenon takes less time to occur for lower front times. Simulation results also show that although flashoveroccurred across the insulators placed on two horizontal ends of the transmission tower for lightning strike onthe overhead ground wire and top of the tower, no flashover has occurred across the insulator placed on thehorizontal midpoint of the tower. To implement transmission line surge arresters IEEE, Pinceti and FarnandezDiaz surge arrester models were compared and the one with the better accuracy has been applied to observe theeffectiveness of surge arresters against lightning surges. Three different cases containing different surgecurrents such as direct strike on the overhead ground wire, tower top and phase conductor have been taken intoaccount for the surge arrester performance analysis. The induced overvoltage on the phase conductors with andwithout surge arresters has been analyzed for each cases using ATP Draw. In first two cases the inducedvoltage on the phase conductors are greater than the Basic Impulse Level (BIL). In case of direct strike on thephase, induced voltage is greater than BIL where the lightning strikes. Applying surge arresters has effectivelyreduced the induced voltage below the BIL thus preventing line outages in each case and it has been observedthat for greater induced voltage arrester’s percentage overvoltage suppression becomes higher.Key-Words: - Lightning surge, Transmission Tower model, Flashover, Surge Arrester, ATP/EMTP.EMTP (Electro Magnetic Transient Program),NEC (Numerical Electromagnetic Calculation) andFDTD (Finite Difference Time Domain) methodsare generally used for power system transientanalysis. Among these EMTP or ATP (AlternatingTransient Program) has gained more popularitybecause of its user-friendly environment.Transmission tower modelling is required to studythe lightning transient behavior of a transmissiontower. M. Ishii et al proposed a tower modellingapproach using parallel RL circuits in [1]. In [2], T.Hara implemented a simple distributed line torepresent the equivalent circuit of a transmissiontower. Lightning phenomenon on a transmissiontower was studied using NEC method representingthe tower as an equivalent circuit following T.Hara1 IntroductionLightning surge is a very natural and mostunpredictable phenomenon which may disruptpower system and cause equipment’s failure.Lightning generally strikes on the tall structure ineverywhere. Because of the structural heighttransmission towers and lines are prone to lightningstrike. Lightning can strike the overhead groundwire, tower top and phase a conductor which in turncauses extensive damage to the phase conductorsand insulator strings by inducing overvoltage onphase conductors and across insulator strings.Flashover is also observed when voltages across theinsulators become higher than the insulatorwithstands level and it causes serious damage to thesystem.E-ISSN: 2224-350X88Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMStower model [2] in [3]. In [4], M.Ishii’s proposedequivalent circuit of transmission tower [1] wasadopted to express a 132kV transmission tower forEMTP analysis. In [5], for a 77KV transmissiontower a comparison between tower models in [1]and [2] was conducted. Representing the tower as aloss-less Constant-Parameter Distributed Line, backflashover event was observed across insulatorstrings when lightning strikes the overhead groundwire and phase conductor in [6]. In [7], transmissiontower was expressed in M. Ishii’s proposedequivalent circuit [1] to analyze the performance ofline surge arresters using EMTP-RV software. Itwas stated that direct strike on the overhead groundwire or top of the tower will induce voltage on thephase conductors and across insulator string andinduced voltage on the phase conductors and acrossinsulators was later investigated for back flashoverusing PSCAD in [8].Surge Arresters do not operate under normalvoltage and provide a low impedance path to groundfor a surge wave when lightning strikes. Thus surgearresters exhibit a non-linear behavior. In recentdays, metal oxide or ZnO surge arresters havegarnered more attention for surge protection.According to [9] ZnO surge arrester cannot berepresented only by a non-linear resistance since itsresidual voltage is highly influenced by themagnitude and rate of rise of the surge current andan equivalent model to represent ZnO arrester wasalso proposed by IEEE Working Group in [9].Another model was suggested by Pinceti based onthe preceding model in [10]. Based on the IEEEmodel a simple and effective surge arrester modelwas presented by Farnandez-Diaz in [11]. In [6]Surge arrester was represented by the equivalentmodel presented in [10]. Surge arresters wereimplemented to the power system using Pincetimodel [10] in [7]. Transmission line surge arresterswere represented according to [9] in [12]. Acomparative study between the surge arrestermodels has been conducted for a 132kVtransmission system concluding that the FarnandezDiaz model is more accurate in [13]. In this papereffect of surge front time and tail time duringlightning surge event and performance of surgearresters for a 400kV transmission system have beenstudied.The rest of the papers are organized as follows.Section 2 describes the transmission tower systemwith different parameters. Simulation results havebeen discussed in section 3. Finally section 4concludes the result.E-ISSN: 2224-350X2 Transmission System Modelling2.1 Transmission Line Model400kV transmission tower with two overheadground wires are considered for this study. Thewires are 300km long. ACSR AFL-8 was taken asphase conductors with a resistance of 0.0557 perkilometer [14] and AFL-1, 7 as the overhead groundwires conductors with a resistance of 0.417perkilometer [15]. In ATP Draw phase wires andground wire are modeled separately using LCCtemplate. For simplicity one transmission toweralong with two tower spans has been considered.Line termination at each side is carried out byterminating the phase conductors with AC operationvoltages and grounding the overhead earth wires toavoid any reflection that might affect the simulatedhigh-voltages around the point of impact following[16].2.2 Transmission Tower ModelIn this study M. Ishii’s proposed tower modellingmethod has been applied which is shown in Fig. 1,to model the 400 kV transmission tower presentedin Fig. 2 [17]. Tower surge impedanceiscalculated from CIGRE recommended equation[18]:(1)Where, the equivalent radius of the tower canbe determined with the help of Fig. 3a using thefollowing equation:(2)Fig. 1. Multistory tower model.89Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMS(a)(b)Fig. 2. 400kV transmission tower [17].Fig. 3. Equivalent tower model.Fig. 3b shows the equivalent circuit to representthe tower. The tower modelling equivalentparameters have been calculated from the followingequations [5]:The withstand capability and back flashovermechanism of the insulator string can be expressedas following [19]:(12)Where, flashover voltage, 400*L, 710*L, L insulator length (meter), t elapsedtime after lightning stroke (µs).If voltage between the terminals of the insulatorbecomes equal or greater than the flashover voltagefrom Equation (12), flashover will appear across theinsulator string. Hence the insulator flashover eventsimulation model has been developed using a timedependent voltage controlled switch across theinsulator strings following the flow diagram in Fig.4. During simulation period both the voltage acrossthe insulator is measured and the flashover voltagefrom Equation (12) is calculated simultaneously atan interval of Δt, which is actually the samplingtime of the simulation. At any time instant, thesetwo voltages are compared and if the voltage acrossthe insulator string is equal or greater than theflashover voltage, the switch is closed to simulatethe flashover event at the corresponding timeinstant.(3)(4)(5)(6)(7)(8)(9)(10)Where, surge impedance of the uppersection of the tower, surge impedance of thelower section of the tower, resistance of the RL branch of the upper section of the tower, resistance of the R-L branch of the lowersection of the tower, inductance of the R-Lbranch of theupper section of the tower, inductance of the R- L branch of the lowersection of the tower, attenuation co-efficient, tower travel time, surge velocity and heightof the tower.2.3 Cross Arms Model2.5 Surge Arrester ModelCross arms are modelled as distributed constantlines following [2] and the surge impedanceisgiven by:(11)Where, h height of the cross arm, r radius ofthe cross arm.In present days, Metal Oxide surge arresters gainedmore popularity for surge protection of transmissionsystem. These arresters have high resistance undernormal operating condition but show low resistancewhen system overvoltage occurs. According to [20]for a 400kV transmission system surge arrester of336kV rated voltage is selected.To represent the nonlinear behavior of surgearresters several models have been proposed. IEEE[9] and Pinceti [10] and Farnandez-Diaz [11]models have been chosen for comparison in thisstudy.2.4 Insulator and Back Flashover ModelInsulator strings are represented as capacitor havingequivalent capacitance value of 80pF per unit [19].E-ISSN: 2224-350X90Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSFig. 5. IEEE model.Fig. 4. Flashover simulation model flow diagram.In IEEE model which is shown in Fig.5, the nonlinear characteristics can be achieved using twoarresters separated by an R-L filter. For slow-frontsurges the impedance of the filter is very low andthe two non-linear arresters are practically inparallel. For fast-front surges R-L filter exhibitssignificant impedance resulting more currentthrough A0. Inductance associated with magneticfields near the arrester is denoted by L0. R0 is placedto stabilize numerical integration in simulationsoftware. Capacitance between the terminals of thearrester is denoted by C. The parameters are givenas follows [9]:(13)Fig. 6. Pinceti model.(14)Fig. 7. Farnandez-Diaz model.(15)(16)(19)(17)Where, d estimated height of the arrester, n number of parallel columns of metal oxide in thearrester.Fig. 6 shows Pinceti model which has someminor differences from IEEE model. Thecapacitance between the terminals is eliminated dueto its negligible effect. Instead of two parallelresistors with the inductors a resistance of about1MΩ is placed between the input terminals. Theoperating principle is quite similar to that of theIEEE model. The parameters can be determinedfrom the following equations [10]:Where, Vn Rated voltage of the arrester, Vr8/20 Residual voltage for a (8/20) 10 kA lightningcurrent and Vr1/T2 Residual voltage for a (1/T2) 10kA lightning current.In Farnandez-Diaz model depicted in Fig. 7, onlyinductance between two non-linear branches isconsidered. Terminal to terminal capacitance hasbeen taken into account. Like the Pinceti model, aresistance of about 1MΩ is connected across theinput terminals. Parameters have been calculatedfrom the following [11]:(20)(18)E-ISSN: 2224-350XC91(21)Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMS(22)Where, i(t) instantaneous lightning current, I0 peak value of lightning current,τ1 front time oflightning current,τ2 tail time of lightning current.For back flashover studies crest value of thecurrent source can be as high as 200kA [19]. Fig. 8ashows the surge current 150 kA (3/77.5 µs) that hasbeen selected for direct strike on the overheadground wire in this study following [6]. Accordingto [8] 100kA (1.2/50 µs) and according to [4] 20kA(1/30.2 µs) have been selected for direct lightningsurge on top of the tower and phase A conductorrespectively and shown in Fig. 8b and Fig. 8c.Thelightning strike is modeled by a Hiedler currentsource and a parallel lightning-path impedance of400Ω.(a)3 Simulation and Result3.1 ATP Draw modelSimulation has been carried out in ATP Drawsoftware. The ATP Draw equivalent circuit of thetransmission system is presented in Fig. 9. Thevalues of the parameters are calculated from thepreceding modelling scheme. The value of the towerfooting resistance is considered to be 10 ohms assuch was done in [4]. Length of the insulator stringsis considered to be 4.3m [22].(b)3.2 Observations of Different Effect3.2.1 Effect of Front time and Tail timeFor lighting strike on an overhead ground wire, thefront time of the lightning surge current has aninfluence on the induced voltage on top of thetower. Considering the peak amplitude of the surgecurrent to be 150kA, the induced voltage waveshapes for different front times have been depictedin Fig. 10 which clearly shows that for a lower fronttime the induced voltage will be higher. For thefront time of 1.2µs, 4µs and 6µs the induced voltageon the tower top is 7.8 MV, 7.5 MV and 7.2 MVrespectively.The same analysis has been carried out for tailtime 20µs, 40µs and 60µs which is depicted in Fig.11. It is apparent from the obtained voltage waveshapes that variation of maximum induced voltagefor the same surge current with different tail times isnegligible.(c)Fig. 8. Surge Current Waveforms.Where,Rated voltage of the arrester, Residual voltage for a (8/20) 10 kA lightning current, Vr1/20 Residual voltage for a(1/20) 10 kA lightning current and Residual voltage for a (30/60) 1 kA lightningcurrent.2.6 Lightning ModelLightning current source can be expressed as SingleExponential function, Ramp type function, Doubleexponential function and Hiedler function. Forsimulation purposes Hiedler function [21] has beenmore popular in recent EMTP studies and so it hasbeen selected in this study.E-ISSN: 2224-350X3.2.2 Effect of Surge Front Time on InsulatorFlashoverConsidering the first case scenario which islightning strike on the overhead ground wire with150kA surge current of a fixed tail time. For92Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSFig. 12. Voltage across insulator holding phase Adue to direct strike on overhead ground wire fordifferent front times.Fig. 9. Equivalent system model in ATP Draw.Fig. 10. Induced voltage on tower top for differentfront times.Fig. 13. Voltage across insulator holding phase Cdue to direct strike on overhead ground wire fordifferent front times.Table 1Time to Flashover Occurrence Due To Direct Strikeon the Overhead Ground Wire For Different FrontTimesTime to Flashover OccurrenceFront Front FrontFrontTimeTimeTimeTime1.2µs3µs5µs10µsFig. 11. Induced voltage on tower top for differenttail times.different front times of 1.2µs, 3µs, 5µs and 10µs ofthe surge current function voltage wave shapesacross the insulators have been observed which aredepicted in Fig. 12 and Fig. 13 respectively forinsulators holding phase A and phase C. Table 1presents a better understanding by providing thevariation of time to insulator flashover occurrencewith the variation of front time. It appears thatvoltage shapes across the insulators are highlyinfluenced by the front time of surge current andlower front time causes faster flashover occurrence.E-ISSN: 2224-350XInsulatorholdingphase A3.5µs3.7µs4µs9.5µsInsulatorholdingphase C5.5µs6µs6.8µs8.6µsSimilarly in the next case that is lightning strike onthe tower top 100kA surge current of a fixed tailtime has been injected for different front times of1.2µs, 3µs, 5µs and 10µs. Fig. 14 and Fig. 15illustrates the voltage wave shapes across theinsulators holding phase A and phase Crespectively. Table 2 shows the time to insulatorflashover occurrence for different front times. Forthe insulator holding phase A flashover occurs only93Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSFig. 14. Voltage across insulator holding phase Adue to direct strike on tower top for different fronttimes.Fig.16. Residual voltage of 336kV ABB PEXLIM Qsurge arrester for 20kA (8/20µs) surge current.Table 3Residual Voltage of 336 kV ABB PEXLIM Q SurgeArrester for 20kA (8/20µs) Surge rvoltage inDifferencein DataModelATP(%)sheetDrawFig.15. Voltage across insulator holding phase Cdue to direct strike on tower top for different fronttimes.Table 2Time to Flashover Occurrence Due To Direct Strikeon the Tower Top for Different Front TimesTime to Flashover OccurrenceFrontFront Front lator11.1µs Flash- Flash- Flashholdingoveroveroverphase e C889 kVPinceti883 kVFernandezDiaz879 kV2.3%869 kV1.6%1.15%between the insulators terminals could not intersectthe volt-time characteristic curve.In both cases, no flashover is observed across theinsulator holding Phase B which is installed in thehorizontally middle position of the tower.3.2.3 Surge Arrester PerformanceIEEE Pinceti and Farnandez-Diaz models for theselected surge arrester ABB PEXLIM Q with a ratedvoltage 336kV have been compared by injecting20kA (8/20µs) surge current into each model inATP Draw. The observed residual voltage for IEEE,Pinceti and Farnandez-Diaz Model were 889 kV,883 kV and 879 kV shown in Fig. 16. According themanufacturer’s datasheet residual voltage of thearrester for 20kA (8/20µs) is 869kV [23]. So fromTable 3, it is apparent that the deviation from themanufacture provided data is less for FarnandezDiaz model. Thus Farnandez-Diaz model showsbetter accuracy in this case. Lightning Surge hasbeen considered to hit overhead ground wire.Induced overvoltage shape on the phase conductorsis shown in Fig.17. The maximum overvoltage onphase conductor A, B and C is respectively 3.27MV, 2.49MV and 2.56 MV respectively.for the 1.2µs front time. But for higher front timesthe voltage across the insulator is not severe enoughto intersect the volt-time characteristic curve andhence no flashover has been observed. In case of theinsulator holding phase C, 1.2µs front time surgecurrent causes the fastest flashover. Higher values ofthe front time take longer time for the insulatorflashover to appear. The least severe case whichcontains the surge current of 10µs front time noflashover has been observed as the voltage shapeE-ISSN: 2224-350XIEEE94Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSTable 4Maximum Voltage on Phase Conductors Due ToOverhead Ground Wire Lightning StrikeOverPhaseWithoutWithvoltageConductor ArresterArresterSuppression3.27 MV 0.824 MV74.8%A2.49 MV 0.816 MV67.2%B2.56 MV 0.816 MV68.1%CFig.17. Induced overvoltage on the phaseconductors due to direct strike on overhead groundwire.Induced voltage with surge arresters on the phaseconductors for this case is shown in Fig. 18. FromTable 4, the maximum voltages with surge arresterson the phase conductors A, B and C are 0.824 MV,0.816 MV and 0.816MV when the lightning strikesthe Overhead Ground Wire. Basic Insulation Level(BIL) of the connected equipment and transformer a400 kV transmission system is around. 1.55 MV[20]. Thus it is apparent that transmission line surgearresters have reduced the magnitude of theovervoltage induced on the phase conductors to avalue below the Basic Insulation Level (BIL)preventing line outage.In the next case surge current is injected ontothe tower top. Induced voltage on the phaseconductors is presented in Fig. 19. The observedpeak value of the induced voltage of phases A, Band C conductors are 2.22 MV, 1.67 MV and 1.68MV. Adding transmission line surge arresters hassignificantly reduced the phase conductors inducedvoltage which is shown in Fig. 20 and from Table 5respectively on phase A, B and C peak inducedvoltages are 0.814 MV, 0.8 MV, 0.801MV.Fig.19. Induced overvoltage on theconductors due to direct strike on tower top.Fig.20. Induced overvoltage on the phaseconductors due to direct strike on tower top withsurge arrester.Table 5Maximum Voltage on Phase Conductors Due ToTower Top Lightning StrikePhaseWithoutWithOver-voltageConductor Arrester ArresterSuppression2.22 MV 0.814 MV63.3%A1.67 MV 0.800 MV52%B1.68 MV 0.801 MV52.3%CSurge current has been imposed on the phaseconductor in the next case to simulate the shieldingfailure event. Phase A conductor was considered tobe hit directly by the lightning impulse current. Theother phase conductors remain unaffected in thiscase. Waveforms of induced voltage on phase Aconductor before and after applying surge arrester isFig.18. Induced overvoltage on the phaseconductors due to direct strike on overhead groundwire with surge arrester.E-ISSN: 2224-350Xphase95Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMSstrings at the two horizontal ends of the tower aremore prone to flashover occurrence during lightningphenomenon. Thus this observation can be takeninto account during tower structure design andtransmission line and insulator string erection toreduce the damage to the insulator string duringlightning surge phenomenon by preventing insulatorflashover.From the simulation results it has been observedthat induced overvoltage on the transmission linescan be much higher than the suggested BasicImpulse Level which may cause line outage orsevere damage to the connected equipment due tothe travelling waves of severe magnitudes for eachof the mentioned three case scenarios. Transmissionline surge arresters have been implemented and it isobserved that surge arresters reduce the inducedovervoltage under the Basic Impulse Level thuspreventing line outage and other equipment failure.A significant observation is that the percentageovervoltage suppression of the arrester is higher forgreater induced voltage and in this study the rangeof the percentage overvoltage suppression is 52% to74.8%. For the protection of electrical equipmentsand power outage from lightning inducedovervoltage this research analysis will play asignificant role.Fig.21. Induced overvoltage on the phase conductorA due to direct strike.Fig.22. Induced overvoltage on the phase conductorA due to direct strike with surge arrester.Table 6Maximum Induced Voltage on Phase A ConductorDue To Direct Lightning StrikeWithoutOver-voltageWith arresterarresterSuppression3.01 MV0.862 MV71.3%References:[1] M. Ishii, et al, “Multistory transmission towermodel for lightning surge analysis”, IEEETransaction on Power Delivery, Vol. 6, No. 3,1991, pp.1327-1335.[2] T. Hara and O. Yamamoto, “Modeling of atransmissiontowerforlightning-surgeanalysis”, IEE Proc.-Gener, Transm. Distrib,Vol. 143, No.3, 1996.[3] M. S. Yusuf, M. Ahmad, M. A. Rashid, and M.O. Goni, “Analysis of Lightning SurgeCharacteristics on Transmission Tower”,Journal of Engineering Letters, Vol. 23, No. 1,2015, pp. 29-39.[4] N. Zawania, Junainaha, Imrana and MFaizuhar, “Modelling of 132kV overheadtransmission lines by using ATP/EMTP forshielding failure pattern recognition”, ProcediaEngineering, Vol. 53, 2013, pp.278 – 287.[5] T. Ueda, T. Ito , H. Watanabe ,T. Funabashiand A. Ametani, “A comparison between twotower models for lightning surge analysis of 77kVsystem”,PowerConInternationalConference on Power System TechnologyProceedings, Perth, WA, Australia, 4-7December, 2000.shown in Fig. 21 and Fig. 22. From Table 6 it isapparent that applying transmission line surgearresters reduced the maximum induced voltagefrom 3.01 MV to 0.862 MV on phase A conductor.4 ConclusionLighting surge response of a 400kV transmissionsystem has been analyzed in details usingATP/EMTP. According to the obtained results, it isapparent that front time of the lighting surge currenthas a great influence on the induced overvoltage andmagnitude of the induced voltage is higher for theshorter front time. But varying the tail time does notsignificantly affect the peak induced voltage value.Insulator flashover simulation results present thatreducing the front time of the surge current causessteeper overvoltage across the insulators thus lowerthe front time causes faster insulator flashoveroccurrence. From Insulator flashover simulationresults it has also been observed that insulatorE-ISSN: 2224-350X96Volume 14, 2019
Md. Salah Uddin Yusuf, Abdul Munem Saad,Monira Islam, Chowdhury Azimul HaqueWSEAS TRANSACTIONS on POWER SYSTEMS[6] M. Kizilcay, C. Neumann, “Lightningovervoltage analysis of a 380-kV overhead linewith a GIL section”, International Conferenceon Power Systems Transients (IPST), Cavtat,Croatia 15-17 June, 2015.[7] S. Mohajeryami and M. Doostan, “Includingsurge arresters in lightningperformanceanalysis of 132kV transmission tower”,IEEE/PES Transmission and DistributionConference and Exposition (T&D), Dallas, TX,USA, 3-5 May, 2016.[8] M. Qais and U. Khaled, “ Evaluation of V-tcharacteristics caused by lighting strokes atdifferent locations along transmission lines”,Journal of King Saud University - EngineeringSciences, Vol. 30, No 2, , 2018, pp. 150-160.[9] IEEE Working Group 3.4.11 “Modelling ofmetal oxide surge arrester”, IEEE Trans. OnPower Delivery, Vol.7, No 1, 1992, pp. 302309.[10] P. Pinceti and M. Giannettoni, “A simplifiedmodel for zinc oxide surge arresters”, IEEETransactions on Power Delivery, Vol. 14, No.2, 1999, pp 393-398.[11] F. Fernandez and R. Diaz, “Metal oxide surgearrester model for fast transient simulations”.International Conference on Power SystemTransients, June, 2001.[12] S. Bedoui, A. BayadiandA. M. Haddad, “Analysis of lightning protection withtransmission line arrester using ATP/EMTP :case of an HV 220kV double circuit line”, 45thInternational Universities Power EngineeringConference UPEC, Cardiff, Wales, UK, 31Aug.-3 Sept, 2010.[13] M. Z. Islam, M. R. Rashed and M. S. Yusuf,“ATP-EMTP modelling and performance testof different type of lighting arrester on 132kVoverheadtransmissiontower”,3rdInternational Conference on ElectricalInformation and Communication Technology(EICT), Khulna, Bangladesh, 7-9 December,2017.[14] SSN: 2224-350X[15] 6] J. A. Martinez-Velasco and Ferley CastroAranda, “Modelling of overhead transmissionlines for lightning studies”, InternationalConference on Power Systems Transients(IPST), Montreal, Canada, 19-23 June, 2005.[17] M. Łoboda and K. Lenarczyk, “Correlationbetween recorded CG lightningdischarges andshut-downs of selected HV overhead powertransmission lines in Poland”, InternationalConference on Lightning Protection (ICLP),Shanghai, China, 2014.[18] CIGRE Working Group 33-01, “Guide toprocedures for estimating the lightningperformance of transmission lines”, TechnicalBrochure, October, 1991.[19] IEEE Task Force on Fast Front Transients,“Modeling guidelines for fast transients,” IEEETransaction on Power Delivery, Vol. 11, No. 1,1996, pp. 493–506.[20] B. Oza, N. Nair, R. Mehta and V. Makwana,Power system protection and switchgear, NewDelhi: Tata McGraw-Hill Education PrivateLtd, 2010.[21] F. Heidler, J.M.Cveti and B. V. Stani,“Calculation of Lightning Current Parameters”,IEEE Transaction on Power Delivery,Vol. 14,No. 2, 1999, pp. 309-404.[22] M. R. B. Tavakoli and B. Vahidi, “AMetamodelingApproachforLeaderProgression Model-based Shielding FailureRate Calculation of Transmission Lines UsingArtificial Netural Network”, Journal ofElectrical Engineering and Technology, Vol: 6,No: 6, 2011, pp 760-768.[23] Library.e.abb.com. (2008). [Online] Q.pdf.97Volume 14, 2019
Lightning surge, Trans. mission Tower model, Flashover, Surge Arrester, ATP/EMTP. 1 Introduction . Lightning surge is a very natural and most unpredictable phenomenon which may disrupt power system and cause equipment's failure. Lightning generally strikes on the tall structure in everywhere. Because of the structural height
steady fl ow from the header tank through the surge pipe. This fl ow creates a measurable head loss (due to friction) along the surge pipe from the header tank to the surge tower. To create the surge, students quickly shut the surge valve downstream of the surge pipe. VDAS displays and records the pressure surge in the surge tower. Students
The surge arrester protects the power systems from both the direct and indirect lightning surge by diverting the charge and energy to ground. In the process of diverting, it clamps the surge on the system from the arrester onward. Since the surge arrester has resistance even in its conductive state it does not reduce the lightning surge to zero.
Lightning stresses - lightning categories - summer and winter lightning Lightning overvoltages and the energy content of a surge depend on the lightning current only and are pure statistically. But only a fraction of the lightning current wil
Creating new Lightning Page using Lighting App Builder Salesforce Lightning pages can be created using Lightning App Builder. To create, navigate to Build Lightning Bolt Lightning App Builder New. Lightning App Builder - App page. In this step, select App page and click on next button as shown below. Lightning App Builder
The coincidence of wind surge, spring high tide and external surge leads to extreme storm surge levels along the coast (figure 4). Figure 4: The components of a storm surge. Thus a storm surge is composed of the local tides, wind surge and a possible external surge. In the project storm surges from 1901 until 2008 at tidal gauge
2021 ANNUAL LIGHTNING REPORT V aisala 2022 Global lightning detection for more than 10 years. Vaisala's owned-and-operated . Global Lightning Dataset GLD. 360 is the only truly global lightning detection network and has been detecting lightning around the planet since 2009. It is the most advanced and accurate long-range lightning detection .
voltage calculation is explained by Juan A. Martínez et al. in [11]. Mohd Z. A. Ab Kadir et al. analyzed back flashover, . analysis of lightning surge phenomena clearly. Then the study in this paper precedes the work done to obtain, the surge characteristics of an earth-wired tower as well as phase conductors of the tower struck by lightning .
Sometimes referred to as a ‘mini-stroke’ or ‘warning stroke’ – an event is defined as a TIA if the symptoms resolve within 24 hours. . 1 in 8 strokes are fatal within the first 30 days. 1 in 4 strokes are fatal within a year. Stroke is the fourth single largest cause of death in the UK and second in the world. By the age of 75, 1 in 5 women and 1 in 6 men will have .
