The development of the advanced distribution automation system with optical fiber network of Tokyo electric power Co., Inc

In the late 1980's, Tokyo electric power Co., Inc. (TEPCO) had developed the distribution automation system (DAS). Since then, the DAS has expanded into all branch offices. The existing DAS can't monitor the detailed data of the distribution network. But, monitoring of detailed data becomes more significant because the recent acceleration of introducing dispersed generators to the distribution network and the deregulation in electricity supply industry to be extended to the distribution network are changing the circumstances of the distribution network. So, TEPCO, TMT&D and other manufacturers have jointly developed the advanced DAS with an optical fiber network. This system will be installed in the actual field of TEPCO and subjected to the field test from January 2004 in order to prove its effectiveness.

I. Introduction

Most distribution networks of Tokyo Electric Power Co., Inc. (TEPCO) are adopting the 6.6kV non-grounding system. The remaining networks, for small areas, are adopting the 11.4kV or 22kV system. In the late 1980's, TEPCO had developed the Distribution Automation System (DAS), which monitors and controls the 6.6kV distribution network. Since then, the DAS has expanded into all branch offices. The DAS consists of Remote Terminal Units (RTUs), and the computer system that monitors and controls all the RTUs in the district office. TEPCO adopted the Distribution Line Carrier (DLC) for the transmission between the computer system and RTUs.