報告書番号

T91093

タイトル（和文）

５００ｋＶ試験送電鉄塔の雷サージ特性

タイトル（英文）

FIELD TEST OF LIGHTNING SURGE ON 500-KV TESTTRANSMISSION TOWER

概要 （図表や脚注は「報告書全文」に掲載しております）

塩原実験場の５００ｋＶ試験送電線を用いた雷サージ実験結果を主に述べたものである。実験では高さ約４８ｍの鉄塔の上あるいは地上におかれたパルス発生器により矩形波電圧を印加した場合の鉄塔のサージインピーダンスの測定および地上から雷撃電流に近い電流波形を衝撃電圧発生器により印加した場合等の各部の測定を行っている。この中では印加法，測定補助線による影響についても論じている。また，鉄塔サージインピーダンスの大きさが変電所侵入雷サージの大きさに与える影響についても解析的に得て述べてある。

概要 （英文）

THIS PAPER DESCRIBES A LIGHTNING SURGE TEST ON A 500-KV TEST TRANSMISSION TOWER AND TRANSMISSION LINE. THE TOWER WAS 48.2-M HIGH. THE POTENTIAL AND CURRENT WERE MEASURED AT MANY POINTS ON THE TOWER INCLUDING ARMS;THE LINE AND TOWER FOUNDATION POTENTIAL AND TOWER-TO-LINE VOLTAGES WERE ALSO MEASURED. THE TOWER POTENTIAL WAS MAINLY MEASURED BY A TOWER-TO-FAR-END GROUNDED 48.2-M WIRE. THE MAIN RESULTS ARE AS FOLLOWS: (1)THE MEASURED TOWER IMPEDANCE WAS 125 OMEGAS,AND THE VELOCITY OF THE VOLTAGE SURGE WAS ABOUT 20% SLOWER THAN THE VELOCITY OF LIGHT. (2)THE MEASURED TOWER IMPEDANCE DEPENDS ON THE MEASURING METHOD. IF THE CURRENT SOURCE IS AT THE EARTH LEVEL,THE TOWER SURGE IMPEDANCE WAS FROM 90 TO-660 OMEGA WHEN THE MATCHING RESISTANCE OF THE TOWER TOP CHANGED FROM 0 TO 15,600 OMEGA. (3)THE UPPER VARIANCE OCCURS ON THE TRAVERSING CURRENT WAVE. IF THE CURRENT SOURCE IS AT THE EARTH LEVEL,THERE IS A REAL TOWER SURGE IMPEDANCE BECAUSE THERE IS NO INDUCED REFLECTION AT THE TOWER TOP. HOWEVER THIS VALUE IS NOT MEANIGLESS WHEN LIGHTNING CURRENT FLOWS IN THE TOWER. (4)THE MEASURED TOWER-TO-LINE OVERVOLTAGE IS NEARLY THE SAME AS THE TOWER POTENTIAL.

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