報告書番号

T99042

タイトル（和文）

需要地系統の構成のための基礎検討 -電圧変動から見た需要地系統構成の検討-

タイトル（英文）

Basic study on configuration of demand side power system :A study on the configuration of demand side power system from the viewpoint of voltage fluctuation

概要 （図表や脚注は「報告書全文」に掲載しております）

将来の需要地域に近い電力系統では、大量に分散型電源が導入され、現状系統では対処できなくなる。これに対し、当所では需要地系統という概念を提案しており、その実現には現状配電系統の問題点の整理と、構成・運用方式の構築が必要である。 本報告では、現状配電系統に分散型電源が導入された場合の、問題点の抽出を行った。また、分散型電源の導入率、電圧変動、負荷密度の関係を電圧階級毎に解析し、電圧管理面より需要地系統の系統電圧は２２ｋＶが望ましいことを明らかにした。また、繁華街と住宅地域の配電線モデルに太陽光発電装置を導入した系統で、詳細な解析を行い、亘長と分散型電源の導入率の関係を示した。さらに、ループ化することで電圧変動を抑制できるが、地絡保護や短絡保護において、誤動作や検出感度の低下が発生し、また、短絡容量が増大するなど、従来の保護方式ではループ系統の保護は困難であることが明らかとなった。

概要 （英文）

In the future, many dispersed generators will be situated near demand areas. In a demand side power system, power flow is large and the power system cannot be controlled using a conventional power system. To cope with this condition, the configuration of future of demand side power systems must be flexible in consideration of the loop and mesh configuration, so that its voltage class and trunk transmission system configuration can be simplified. In order to realize such a demand side power system, the image of the future network configuration and the method of converting the conventional distribution system to a demand side power system must be clarified and concepts of operation and control, network protection, interconnection and protection for dispersed generators must be proposed. In this paper, we select the most important problem of many in conventional power system by analyzing power flow and line voltage. If dispersed generators supply electricity freely, the feeder voltage exceeds the limit of the conventional power system. The relationships of dispersed generator output, voltage fluctuation, and load density were shown at system voltages of 6.6 kV, 22 kV and 66 kV. Results revealed that a system voltage of 22 kV is the best choice for a demand side power system. Calculations of voltage fluctuation in a power system consisting of an urban model feeder and a residential model feeder showed a relationship between feeder length and dispersed generators output limit. One of a number of problems we identified in a conventional power system connected to many dispersed generators was that power couldn't flow when dispersed generators are freely separated the feeder. Analysis of a loop power system fault showed that a loop power system cannot be protected by a conventional protection system.

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