Study of Lightning-Surge Overvoltages at Substation due to Direct Lightning Strokes to Phase Conductors

Abstract

(Tokyo Electric Power Company) Lightning observations have been made to study the lightning phenomena on UHV designed transmission line. And many shielding failures not to be predicted by the conventional shielding theory have been observed. This paper describes the study of lightning-surge overvoltages at substations caused by direct lightning strokes to phase conductors on transmission lines. The overvoltages were evaluated to compare with the overvoltages due to back flashover and the lightning impulse withstand voltage. The direct lightning current used for the calculation was set up by the analysis of a result of observation. And, this report explains effects of capacitance of a transformer and an arrester upon overvoltages at a primary terminal of a transformer. Transient calculations were performed by the EMTP. ƒL •[ ƒ••[ ƒh:•Ï "d"Ñ,-‹ƒT •[ ƒW ‰ß "dˆ³,ŽÕ ‚Ö‚¢Ž¸"s,"d-Í •ü'¼OE‚-‹,EMTP Keywords: substation, lightning-surge overvoltage, shielding failure, direct lightning stroke to phase conductor, EMTP 1.‚Ü ‚¦ ‚ª ‚« •¡ "ú,UHV'-"d OEv ‰ae(1)‚ð‚Í ‚ ¶ ‚ß ‚AE‚· ‚é "d-ÍOEn"• ‚Ì •‚ ˆ³ ‰» •E 'å-e-ʉ»‚ª •i ‚Þ ' †,'-•Ï "d •Ý"õ ‚Ì ƒR ƒX ƒg'á OE¸‚ðOE¸‚ð Žw OEü ‚µ ‚½ • ‡-• "I ‚È •â ‰• •Ý OEv‚ª Še •û-Ê ‚Å OEŸ"¢ ‚³ ‚ê ‚Ä ‚¢ ‚é(2)•B "d-Í‹@ Ší ‚Ì •â ‰• •Ý OEv‚Å,"Á ‚É •d-v ‚AE ‚È ‚é ‚Ì ‚ª-‹ ƒT •[ ƒW"d ˆ³ ‚ð •³ Šm ‚É-\'ª ‚· ‚é ‚± ‚AE‚Å ‚ ‚é •B •Ï "d •Š ‚Å ‚Ì-‹‰ß"d ˆ³ ‰ð•Í ‚ÍEMTP(Electro-Magnetic Transients Program)‚ð-p‚¢ ‚Ä •s ‚í ‚ê,-‹ OE‚ •ð OE•‚Í, •u •Ï "d •Š ‚© ‚ç OE©‚Ä 'aêê "S "ƒ ‚É-‹OE‚ ‚µ,•ã 'Š ‚Å ‹t ƒt ƒ‰ ƒb ƒV ƒI •[ ƒo ‚ª "-• ¶ ‚µ ‚Ä ƒT •[ ƒW‚ª •Ï "d •Š ‚É •N "ü ‚· ‚é •ê • ‡•v ‚ª •W •€ ‚AE ‚³ ‚ê ‚Ä ‚¢ ‚é(3)•B ‚± ‚ê ‚Í "¯ ‚ ¶ "-• ¶ •p "x ‚Å ‚Ý ‚½ •ê • ‡,‹t ƒt ƒ‰ƒb ƒV ƒI •[ ƒo Žž ‚É "-• ¶ ‚· ‚é •N "ü-‹ƒT •[ ƒW‰ß"d ˆ³ ‚ª '¼ OE‚-‹Žž ‚É "ä ‚× ‚Ä 'å ‚« ‚¢ ‚AE ‚Ì •] ‰¿‚É ‚ae ‚é ‚à ‚Ì ‚Å ‚ ‚é ‚ª,'¼ OE‚-‹ ƒT •[ ƒW‰ß"d ˆ³ ‚É ŠÖ ‚µ ‚Ä ‚Í •Ú •× ‚È OEŸ"¢-Ⴊ ‚Ü ‚¾ •-‚È ‚¢ •B ‹ß "N,UHV•Ý OEv'-"d •ü(ˆê •"500kV•Ý OEv'-"d •ü)‚É ‚¨‚¢‚¨‚¢ ‚Ä ,-Ž-‹ ‚© ‚ç •Ï "d •Š •N "ü ƒT •[ ƒW‚É ‚¢ ‚½ ‚é OEn "• ‚ðˆê‚ðˆê ŠÑ ‚µ ‚½-‹ OE»•Û ‚Ì ŠÏ 'ª ‚ª •s ‚í ‚ê(4)(5),ŽÕ ‚Ö ‚¢ Ž¸"Ž¸"s ‚É ‚ae ‚é "d-Í•ü ‚Ö ‚Ì '¼ OE‚-‹ ‚Ì "-• ¶ ‚ª Šm "F ‚³ ‚ê ‚Ä ‚¢ ‚é •B '¼ OE‚-‹ ‚Ì OE´ˆöOE´ˆö ‚AE ‚µ ‚Ä,UHV•Ý OEv'-"d •ü ‚ª ŽRŠx 'n ‚ð 'Ê ‰ß ‚µ ‚Ä ‚¢ ‚é ‚± ‚AE‚â,•]-ˆ ‚Ì '-"d •ü ‚ae ‚è ‚à "S "ƒ •‚ ‚ª •‚ ‚-'Š ŠÔ‹-£ ‚à 'å ‚« ‚¢ ‚± ‚AE ‚ª •l ‚¦ ‚ç ‚ê ‚é ‚ª, ŠÏ 'ª OE‹ ‰Ê‚ae ‚è •]-ˆ ‚Ì ŽÕ ‚Ö ‚¢-•˜_ ‚Å ‚Í •à-¾‚Å ‚« ‚È ‚¢ ŽÕ ‚Ö ‚¢ Ž¸ "s ‚Ì "-• ¶ ‚à-¾ ‚ç ‚© ‚É ‚È ‚Á ‚Ä ‚« ‚½(6)•B ‚± ‚ê ‚Ü ‚Å ‚Ì '¼ OE‚-‹‰ß"d ˆ³ ‰ð•Í ‚ňà‚Åˆà ‚¢ ‚ç ‚ê ‚é 'z 'è '¼ OE‚-‹ "d-¬'l ‚É ‚Í,ArmstrongŽ• ‚AE WhiteheadŽ• ‚ª 'ñ ˆÄ ‚µ ‚½ŽÕ ‚Ö ‚¢-•˜_(A-W-• ˜_)(7)‚É Šî ‚à ‚« ŽZ •o ‚µ ‚½ 'l ‚ª •Ì-p ‚³ ‚ê ‚Ä ‚¢ ‚é ‚ª,•]-ˆ ‚Ì ŽÕ ‚Ö ‚¢-• ˜_ ‚AEŠÏ 'ª OE‹ ‰Ê‚ňىʂň٠‚È ‚é OEXOEü‚ªOE© ‚ç ‚ê,•]-ˆ ‚Ì 'z 'è '¼ OE‚-‹ "d-¬'l ‚ae ‚è ‚à ŠÏ 'ª OE‹ ‰Ê‚© ‚ç ‹• ‚ß ‚½ •" 'è "d-¬'l ‚Ì •û ‚ª 'å ‚« ‚-‚È ‚é OE‹ ‰Ê (6) "¾ ‚ç ‚ê ‚Ä ‚¢ ‚é •B ‚» ‚± ‚Å-{ ˜_ • ¶ ‚Å ‚Í,ŠÏ 'ª OE‹ ‰Ê‚ae ‚è "¾ ‚ç ‚ê ‚½ 'z 'è '¼ OE‚-‹"d-¬ 'l ‚ð-p‚¢ ‚½EMTP‰ð •Í ‚É ‚ae ‚è,'¼ OE‚-‹ Žž ‚ÉUHVOEn "• •Ï "d •Š "à ‚ÌGIS‚¨‚ae ‚ÌGIS‚¨‚ae ‚Ñ •Ï ˆ³ Ší ‚É "-• ¶ ‚· ‚é ‰ß"d ˆ³ ‚É ‚ ‚¢ ‚Ä •Ú •× ‚È OEŸ "¢ ‚ð •s ‚Á ‚½ •B OEŸ"¢ ‚Å ‚Í,GIS‚¨‚ae GIS‚¨‚ae ‚Ñ •Ï ˆ³ Ší ‚É "-• ¶ ‚· ‚é '¼ OE‚-‹ ‰ß"d ˆ³ "g OE`OE`‚ð ŽZ •o ‚µ,‹t ƒt ƒ‰ƒb ƒV ƒI •[ ƒo Žž ‚¨‚ae‚¨‚ae ‚ÑLIWV(-‹ ƒC ƒ" ƒp ƒ‹ ƒX ŽŽ OE±"d ˆ³)(8)ˆó ‰ÁŽž ‚Ì ‰ß"d ˆ³ "g OE`OE`‚AE'Š OEÝ"ä Šr ‚· ‚é ‚± ‚AE ‚É ‚ae ‚è '¼ OE‚-‹ ‚ð •â ‰• ‹¦ '² ‚Ì ŠÏ "_ ‚© ‚ç •] ‰¿ ‚µ ‚½ •B ‚Ü ‚½, •Å 'å "-• ¶ "d ˆ³ ‚AE-‹ OE‚ "d-¬‚Ü ‚½ ‚Í •Ï ˆ³ Ší ƒL ƒƒ ƒp ƒV ƒ^ ƒ" ƒX ‚Ì ŠÖ OEW ‚𠎦 ‚µ,•Å 'å ‰ß"d ˆ³ "-• ¶ ‚Ì ƒ• ƒJ ƒj ƒY ƒ€ ‚É ‚ ‚¢ ‚Ä ‚à OEŸ"¢ ‚ð ‰Á‚¦ ‚½ •B ‚È ‚¨,‰ð •Í ‚É ‚ÍATP-EMTP‚ð-p‚¢ ‚½ •B 2.‰ð •Í •ð OE• UHV•Ý OEv'-"d •ü ‚AEUHV•Ý OEv•Ï "d •Š ‚ð ‰ð•Í 'Î •Û ‚AE ‚µ ‚½ •B •}1‚ÉUHV'-"d •ü ‚Ì ‰ð•Í-p‰ñ˜H ‚ð,•}2‚ÉUHV•Ï "d •Š ‚Ì ‰ð•Í-p‰ñ˜H ‚𠎦 ‚µ,•\1‚É ‰ð•Í •ð OE• ‚ð ‹L ‚·(9)(10) •B "S "ƒ ƒ‚ ƒf ƒ‹ ‚Í4'i ƒ‚ ƒf ƒ‹ ‚ð Žg-p ‚µ,UHV"S "ƒ ‚Å ‚Ì ŽÀ 'ª ‚É Šî ‚à ‚-'è •" ‚ð Žg-p ‚µ ‚¾(11)•B ‚Ü ‚½,‰ð •Í OE‹ ‰Ê‚É 'å ‚« ‚-‰e‹¿ ‚· ‚é "ð-‹Ší ƒ‚ ƒf ƒ‹ ‚ÍIEEE‚Å 'ñ ˆÄ ‚³ ‚ê ‚½ ƒ‚ ƒf ƒ‹(12)‚ð Žg-p ‚µ ‚Ä ‚¨‚肨‚è,‚» ‚Ì '¼ 856