The application of feeder automation systems has been spreading gradually from large service offices to medium ones. The functional distributed feeder automation system has become the mainstream accordingly. Information networks enhanced by the diffusion of feeder automation systems and the recent development of electronic WHMs have accelerated service automation, mainly automatic meter reading systems, from the stage of research to that of development for practical use. This paper describes the present status and prospect of these distribution automation systems.

Fuji Electric started tackling feeder automation for The Tokyo Electric Power Co., Inc. in 1982 and has supplied systems for Chiba, Numata, Urawa and other business offices totalling ten since full-scale application started in 1991.
This paper mainly introduces the wide-use system type IIdeveloped for The Tokyo Electrical Power Co., Inc. and refers to technical support to the said firm's development group, an outline of the standard system and technical know-how transfer to Toko Electric Corp.

The Kansai Electric Power Co., Inc. and Fuji Electric jointly tackled practical use of distribution automation systems to shorten out-of-service time and to realize more efficient system operation and management and will install them to all the business offices by the end of 1993.
The system realizes easy operation with functions of displaying a distribution system on a street map and screen-input-type facility data maintenance. It adopts AI load management calculation to get operator's know-how. It has further functions such as a monitor system using the latest optical sensors and an information sending system to others.

Fuji Electric developed a feeder automation system for Koriyama Business Office, Tohoku Electric Power Co., Inc. which started operation from March 1992.
This paper introduces the distributed system structure characteristic of this system and the function of automatic distribution system mapping. It refers to other system functions such as failure restoration operation, power cut operation for works, and data maintenance.

Aiming at service improvement to customers by quick restoration in case of a failure and the efficient operation and management of distribution systems, The Chugoku Electric Power Co., Inc. and Fuji Electric jointly developed distribution automation systems for large-scale service offices.
This system has an open distributed configuration with more than one UNIX work-station connected by a LAN and structures a compact, expandable, high-reliability system.

The Tokyo Electric Power Co., Inc. and 7 joint research companies including Fuji Electric started field test of automatic meter reading systems for a total of about 6,000 houses in 3 fields of The Tokyo Electric Power Co., Inc.: Hiratsuka Business Office of Kanagawa Branch, Ome of Tama and Toshima of Tokyo-nishi. The systems aim to get around difficulties in reading meters in apartments and in mountainous regions and efficiently use existing lines such as telephone lines, low-voltage distribution lines and high-voltage distribution lines for distriution automation as transmission lines. It is expected they will be put to wide practical use.

Automatic reading systems collect consumer's power consumption data automatically through communication lines. It is desired to put them to practical use early to improve meter reading efficiency in mountainous regions and to get around difficulties in reading apartment meters. Kyushu Electric Power Co., Inc. and Fuji Electric jointly developed an electronic watt-hour meter common for 1-and 2-hour band.
This paper describes the standard because the watt-hour meter is a legal measuring instrument and then introduces an outline of the design concept, functions, communication specifications and performance.

New Energy and Industrial Technology Development Organization is carrying out "Research on demonstration tests of the load management systems" to establish technologies for load leveling and for saving energy toward the 21st century.
This research is carried out in two projects, Phase Iand Phase II. Central Institute of Electric Power Industry commissioned for Phase II has recently started operating the demonstration system at Akagi Test Center. Fuji Electric manufactured this system following Phase I. This paper introduces an outline of the system and customer's equipment.

As electric power demand increases and reliable power supply is demanded, an "advanced regular-network distribution system" to meet distribution automation is under investigation. In this new system, to automate the system and to isolate a fault area automatically for restoration, it is necessary that switches among distribution network system components can be controlled remotely. Under the circumstances, we developed a GTO current-limiting device which can be used in place of conventional current-limiting fuse. This paper describes an outline of the new device.

Fuji Electric installed a new large-capacity short-circuit testing facility of rated voltage 17kV and short-circuit capacity 2,000 MVA in Chiba Works in July 1992.
The basic plan is as follows:
(1)Short-circuit test of 63kA, the largest short-circuit capacity in Japan.
(2)Environmental protection for noise and vibration.
(3)Saving energy and labor using automatic control.
(4)Labor-saving predictive maintenance with a diagnosis system.

A generator with a short-circuit capacity of 2,000MVA for Fuji Electric Corporate Research and Development Ltd. was manufactured, tested in detail to verify performance, and put into commercial operation in June 1992.
This unit of a 2-pole horizontal cylindrical revolving field type was completed utilizing Fuji Electric's latest technology. To meet the short-circuit current specification of 50kA with star connection/63kA with delta connection, it was designed so that reactance and short-circuit current attenuation can be reduced and it can withstand electromagnetic force and torque caused by short-circuiting.

The supervision and control system for the new 2,000MVA short-circuit generator and the status-monitor system for the testing and other circuits are automated, resulting in greatly simplified operation and easy maintenance.
This paper introduces the automated protection, monitor, and control systems in the installation.