報告書番号

T92019

タイトル（和文）

直流送電線下のイオン流帯電電圧－もれ抵抗と風の影響を考慮した予測法の開発－

タイトル（英文）

METHOD OF PREDICTING CHARGED VOLTAGE INCLUDING EFFECT OF LEAKAGE RESISTANCE OF OBJECTS AND WIND EFFECT UNDER HVDC TRANSMISSION LINES

概要 （図表や脚注は「報告書全文」に掲載しております）

試験線下の実測に基づいて，帯電体のもれ抵抗と帯電電圧との関係を帯電体周囲の空間電位を用いて整理し，これまで考慮されていなかったもれ抵抗の湿度特性と風の影響を考慮できるイオン流帯電電圧の予測法を提案した。主な結果は以下のとおりである。１．帯電体周囲のイオン流場が高電界低イオン電流密度になるほど，もれ抵抗による帯電電圧の増加が大きくなるため，従来の方法にくらべて電線地上高の増加による帯電電圧の低減が小さくなることを明らかにした。２．帯電電圧の目標値に対する所要電線地上高は，従来の方法と大きな差はない。３．風の発生分布を考慮した予測値（１％値）は，年間の１％値とよく一致した。４．風の影響はもれ抵抗が高くなるほど小さくなる。

概要 （英文）

THIS REPORT DESCRIBES A METHOD FOR PREDICTING THE CHARGED VOLTAGE OF OBJECTS UNDER HVDC TRANSMISSION LINES BY CONSIDERING THE EFFECT OF HUMIDITY ON LEAKAGE RESISTANCE OF OBJECTS,AND THE WIND EFFECT:THESE EFFECTS HAVE NOT BEEN CONSIDERED UNTIL NOW. THIS METHOD IS BASED ON THE MEASURED RELATIONSHIP BETWEEN CHARGED VOLTAGE AND LEAKAGE RESISTANCE CHARACTERIZED BY THE SPACE POTENTIAL SURROUNDING THE OBJECTS. THE MAIN RESULTS ARE AS FOLLOWS:(1)THE CHARGED VOLTAGE INCREASES GREATLY WITH INCREASED LEAKAGE RESISTANCE IN HIGH ELECTRIC FIELDS ANDLOWER ION DENSITIES. THEREFORE,THE RATE AT WHICH THE CHARGED VOLTAGE IS REDUCED BY THE CONDUCTOR HEIGHT IS SMALLER FOR VALUES PREDICTED BY THIS METHOD THAN BY THE PREVIOUS METHOD,WHICH ASSUMED THAT THE LEAKAGE RESISTANCE IS CONSTANT AND THE CHARGED VOLTAGE IS PROPORTIONAL TO THE SQUARE ROOT OF THE LEAKAGE RESISTANCE. (2)PREDICTED VALUES ARE NOT MARKEDLY DIFFERENT BETWEEN THIS METHOD AND THE PREVIOUS METHOD AT CONDUCTOR HEIGHTS CORRESPONDING TO THE CHARGED VOLTAGE DESIGN LIMIT. (3)THE PREDICTED 1% VALUE BASED ON THE WIND OCCURRENCE PROBABILITY IS SIMILAR TO THE STATISTICAL 1% VALUE MEASURED THROUGH THE YEAR. (4)THE WIND EFFECT ON THE CHARGED VOLTAGE BECOMES SMALLER AT HIGHER LEAKAGE RESISTANCE.

報告者

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