報告書番号

U33

タイトル（和文）

電力系統の地震リスク評価に基づく変電設備の耐震補強計画法に関する研究

タイトル（英文）

A study on seismic retrofit planning method of substation components on the basis of the seismic risk assessment of electric power system

概要 （図表や脚注は「報告書全文」に掲載しております）

兵庫県南部地震後，変電設備の耐震対策のあり方について検討がなされ，現行の耐震設計基準に準拠していない古い変電設備の耐震補強問題がクローズアップされた．しかし，全ての設備を，一律にかつ短期的に最新の基準に準拠するように改修または補強することは莫大な補強コストが必要となり，難しい状況にある．本研究は，地震リスクと補強コストおよび企業損失コストとの関連を定量的に評価し，合理的な変電設備の耐震補強法を立案するための方法論を検討することを目的としている．提案する耐震補強計画法は，たとえ，現行の耐震基準に準拠していない設備であっても，必ずしもすべて一律に補強する必要はないという方針に基づいている．総費用と耐震対策効果を勘案しながら決まったコストの範囲内で効果的に地震リスクを低減するために，変電設備の補強優先順位を決定し，補強すべき設備を選定できることが，本研究で提案する方法論の最大の特徴である．

概要 （英文）

A lot of seismic countermeasures for electric power systems have been studied to reduce their seismic risk in Japan. For example, a seismic design guide line for substation components constituting electric power system, JEAG5003, was published in 1980 after a research on their damage due to the 1978 Miyagi-Ken Oki earthquake.Physical damage, however, has occurred to substation components due to recent earthquakes even after 1980. Especially, the 1995 HyogoKen Nanbu earthquake caused serious damage to such components and their damage caused widespread power failure to customers. The damage concentrated on pre-existing components built before 1980, which were not designed in accordance with JEAG5003. After the 1995 Hyogoken Nanbu earthquake, it was pointed out by a government commission report that seismic retrofit was needed for those pre-existing components which did not accord with JEAG5003. However, it is difficult to retrofit all pre-existing components in short time, since huge number of pre-existing components has remained non-renewable or non-retrofitting because of prohibitive costs for upgrading.This paper presents a seismic retrofit planning method for substation components on the basis of the assessment of the retrofit cost, and the economical loss associated with the seismic risk of electric power systems. The proposed method suggests that even if pre-existing components do not satisfy existing guide for seismic design, those components are not always needed to be upgraded. The proposed method makes it possible to determine an optimum number and priority of substation components to be retrofitted to reduce the seismic risk rationally within limited budget.

報告者

キーワード