報告書番号

W99027

タイトル（和文）

50kA級長ギャップ交流大電流アークにおけるアークジェット部の温度特性 - －分光計測時の輝線スペクトルの自己吸収を考慮した温度測定手法の開発－-

タイトル（英文）

Temperature of Arc Jet of 50kA Class AC Arc in Long Gap -Development of Spectroscopic Determination of Temperature in Consideration of Self-absorption of Spectral Line-

概要 （図表や脚注は「報告書全文」に掲載しております）

基幹送電線が一層緊密に連系され，故障時の短絡電流が80～100kAに大幅に増大することが想定されている。この故障時に電極から吹出す高温・高速流のアークジェットが，電力機器の適切なアーク対策技術の開発が重要である。今回，10～50kAの交流水平フリーアークを対象としてアークジェット部の分光計測を行い，電極材料である銅の原子スペクトルおよび大気中水分に起因する水素の原子スペクトルを同時観測した。これらの測定結果と，銅原子スペクトルの自己吸収計算結果とから，アークジェットの真の温度と銅蒸気混入率とを同時算出する手法を開発した。アーク電流が10kAから50kAに増加した場合，真のアーク温度はほとんど変化せず10,000K～11,000Kであり，一方，銅蒸気混入率は0.03％から5％程度へと急増した。

概要 （英文）

A high current fault arc causes damage to surrounding apparatus. In particular, the temperature and velocity of the arc jet spouted from electrodes are high enough to ensure a remarkable thermal influence on the surrounding apparatus. This paper describes the results of spectroscopic observation of arc jets of 10-50kA rms AC arcs at the current peak. The electrodes used in the tests were copper of 40mm in diameter, and the gap length between the electrodes was 3.4m. Main results are as follows.(1)Temperatures were estimated by comparing the intensities of two spectral lines of Cu atoms( 510.5nm, 521.8nm). As the arc current increased from 10kA to 50kA, the estimated temperature decreased from 8,500K to 7,000K. It was assumed that the estimated temperature was lower than the real temperature owing to the self-absorption of the spectral lines, especially in case of high current. The difference between the estimated temperature and the real temperature was calculated in the cases of several copper vapor concentrations.(2)The electron densities of the arc jets were estimated at 3-4*1022 m-3 by measuring the Stark broadening of the H-atom (486.1nm; Hβ). The real temperature calculated by means of the estimated electron density was influenced by the copper vapor concentration.(3)The results (1)&(2) described above were used to estimate both the real temperature and the copper vapor concentration (molar rate) of the arc jet. As the arc current increased from 10kA to 50kA, the real temperature did not change so much (10,000K-11,000K), and the copper vapor concentration increased abruptly from 0.03% to 3%.

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