報告書番号

H04020

タイトル（和文）

電力機器の交流絶縁試験に関する現状調査と絶縁試験による寿命評価の可能性

タイトル（英文）

Investigation on AC Insulation Tests for Power Equipments and Feasibility of Extention of Estimated Lifetime Based on Insulation Test

概要 （図表や脚注は「報告書全文」に掲載しております）

GIS，変圧器，CVケーブルを対象に，長時間V-t特性とその劣化要因をまとめ，現行の長時間耐電圧試験による長期寿命評価の考え方を整理した。また，ワイブル分布に基づく機器の信頼度計算，機器の耐電圧試験法に関して，波形や値の異なる電圧印加による故障確率の考え方を整理した。さらに，再度の耐電圧試験による余寿命評価・リプレース延伸の可能性を検討した。 変圧器，CVケーブルは，現行の劣化検出手段で検出できる程度の劣化が進行し得ることから，再度の耐電圧試験で劣化が加わり，余寿命評価することは困難である。一方，現行の設計寿命で劣化はほとんど起きないと考えられるGISでは，機器のリフレッシュ後，再度の耐電圧試験で余寿命を評価し，リプレース延伸を図れる可能性がある。ただし，現行の長時間V-t特性データ，長期信頼性試験の考え方では，耐電圧試験でリプレース延伸の根拠を与えるのは難しく，異なる電圧印加による絶縁特性に基づいた確率分布評価の検討が必要である。

概要 （英文）

From the viewpoint of strong request of the cost reduction in the electric power equipment, investment in equipment will be controlled and the number of aged equipment will increase in the future. Moreover, the aged equipment is requested to be used to the utmost limit completely by postponing the replacement as much as possible. At this time, it is important discussion how to evaluate and guarantee residual lifetime of the equipment. As a method of the postponement of replacement, there is a possibility of guaranteeing the postponement of replacement by executing the withstand voltage test to the aged equipment again.While, the present standards of AC insulation tests for high voltage power equipment in Japan are based on the reliability evaluation according to the Weibull distribution as fault occurrence probability of the equipment. The present evaluation is not considered properly as it does not take into account non-accidental change of the equipment with time. Recently, the problem concerning the reliability evaluation is pointed out from this respect.In this report, we investigated long time V-t characteristics and the bases of AC insulation tests for GIS, the transformer, and the XLPE cable which are major items of the electric power equipment. Moreover, we arranged the idea of fault probability when two different levels (waveform or value) of voltage are applied to equipment. Finally, we investigated the feasibility to evaluate the residual lifetime by executing the withstand voltage test to the aged equipment again.

報告者

キーワード