報告書番号

T99043

タイトル（和文）

電磁界解析に基づく新しい過渡接地抵抗解析手法の実証

タイトル（英文）

Verifying a novel method for analyzing transient grounding resistance based on the FD-TD method through comparison with experimental results

概要 （図表や脚注は「報告書全文」に掲載しております）

電力設備接地系の過渡特性（過渡接地抵抗特性）の解明は，その雷害防止やコストダウンに極めて重要である。このため当所では，種々の接地系に対して簡便に適用可能な新しい過渡接地抵抗解析手法を提唱している。 本報告では，過渡接地抵抗の実測値と新しい過渡接地抵抗解析手法による解析結果との比較から，その手法の妥当性を実証することを目的とし，以下の結果を得た。。 当所赤城試験センターにおいて接地モデル電極について過渡接地抵抗を測定し，新しい過渡接地抵抗解析手法による解析結果と比較したところ，過渡電流，零電位線による過渡電位，ならびにそれらの比から算出した過渡接地抵抗のすべてについて，時間に対する変化傾向もその値も実測値とよく一致した。 したがって，新しい過渡接地抵抗解析手法は，接地系に係わる過渡現象を極めてよくシミュレートでき，過渡接地抵抗を解析するうえで妥当であることが分かった。

概要 （英文）

There are reports that lightning strikes on bulk transmission lines have caused serious accidents involving electrical apparatus, such as failure of electrical transmission. It is important to analyze the dynamic behavior, in items of transient electric potential, transient current, and transient grounding resistance, of grounding systems of electrical apparatus in order to understand all the phases of such accidents and to apply the results to accident prevention. However, the dynamic behavior has so far been difficult to evaluate. Therefore, a method for the computational analysis of transient grounding resistance (TGR) which is easily applicable in grounding systems under various conditions is highly desirable. This paper presents experimental results of TGR and calculation results using a novel method based on the finite difference time domain method, FD-TD method. The analysis results agree very well with experimental results. This indicatess that the novel method for calculating TGR based on the FD-TD method is very useful. The novel method based on the FD-TD method is expected to facilitate the rational design of grounding systems. The characteristic features of this method are (i) it can be used to simulate propagation phases of a transient electromagnetic field and enable their visualization, (ii) it can be used to calculate transient electric potential, transient currents, and TGR from the propagation phases for transient electromagnetic fields, (iii) because the FD-TD method is a type of computational analysis method in the time domain, the calculated results can be more intuitively and easily understood than those of an analysis method in the frequency domain, and (iv) it can be used to precisely model grounding systems, although there are limitations depending on the computer resources available.

報告者

キーワード