The electric railway is in a very important position as the core of mass transportation facilities; therefore, there are many demands for good-quality services in pursuit of safe, comfortable transportation. To satisfy these requirements more completely, it is necessary to make systems intelligent as a whole, for which electronics application will be most effective. This paper outlines the present status, including some of the developments, and prospects for rolling stock systems and traction substation systems in electric railways mainly on the matters related to electronics application.

Together with the progress of GTO thyristor, AC-motor-driven electric cars have rapidy been put to practical use. Fuji Electric, applying 4500-V 3000-A reverse-conducting GTO thyristors, has developed PWM converter, VVVF inverter, and main transformer for the next-generation Shinkansen trains and DC cars, and carried out overall combined ground test.
The paper describes the main circuit system developed by the company, features of the equipment, and the combined test result.

Tokai JR started to use new Series-213 electric cars in Kansai-line from March 1989, and Fuji Electric had participated in the engineering of the electrical system. Coordination design was made between an electric car traction system using a superposed motor field exciting system and auxiliary power system using a low-voltage DC supply system, and up-to-date transistor application technology was included in the electrical systems of superposed field exciters and auxiliary-circuit loads.
Thus compactness, light weight, and energy saving as a total system have been improved. The paper describes an outline of the electrical system, the equipment manufactured by Fuji Electric, and the result of combined tests.

New JRs have actively put new-type cars to practical use. New Series 783, 811, and 719 have been adopted for the old-line AC cars, which were improved in size, weight, performance, and economical efficiency.
This paper describes an outline of the main control rectifiers of Fuji make, RS400K, RS401K, and RS52, together with each car traction system, and the control system for AC regenerative braking systems for Series 783 and 719 as well.

Owing to recent progress in power electronics technology, static power converters of easy maintenance, small size and light weight and low noise have increasingly been used for auxiliary power supplies for rolling stock.
Fuji Electric has manufactured and various many auxiliary supplies using static converters.
This paper outlines some of its recent supplies for (1) Series-721 suburban AC cars, (2) Series-24 passenger cars, and (3) KIHA Series-85 express diesel cars.

The paper outlines large gate-turnoff(GTO) thyristors (4500V,3000A, anode short, reverse blocking, reverse conducting) developed by Fuji Electric. It also describes the present status and prospects for large GTO thyristor application technology, mainly on cooling technology, used in semiconductor converters for rolling stock.

The conventional system for coolers of electric trains has been to convert DC overhead-line voltage into AC by auxiliary power supplies and to drive coolers by induction motors. Coolers for rolling stock require small size and light weight compared with those for building use. Fuji Electric has developed a DC cooler system in which overhead-line DC power directly drives DC motors, resulting in user's satisfaction. This system dose not require power supplies; therefore, it is more suitable for trains of one or few cars and for cooler modification in respect of total space for cooler installation, weight, and expense than the AC systems. The paper introduces the feature, system, and

The total management system has been planned in electric railways, mainly in recent subways, aiming to integrate the management for equipment related to operation and to accomplish closer cooperation of daily operation work and maintenance work. Investigation at the time of planning and system preparation are important to proceed with the management precisely.
This paper describes the points for planning such a system and fuji Electric's system design philosophy. Also it introduces an outline of Sapporo-city Traffic Bureau's management system which has totally managed various equipment including electric power, disaster prevention, signals, and communications.

Recent progress in control and protection technology for traction substations and distributing substations for railway stations are remarkable. Unit or box type digital protective relays are under production besides the conventional panel mount type ones. As for control equipment, distributed types have come into wide use. Centralized supervisory control equipment have mostly included microcomputers. Monitors and recorders utilizing personal computers are employed in monitoring systems.
The paper introduces Fuji Electric's hardware, system configurations functions, and features in connection with these new developments.

Power electronics applications to traction power systems include traction rectifiers, regenerated-power absorbers semiconductor DC breakers, and so on. This paper describes an outline of the whole application systems and some delivered systems. In addition, it refers to a new DC feeding system under study. This system feeding 3000-V DC can apply to 1500-V cars and has much merit in reducing railway electrification cost because of existing car application and reduction in the number of substations.

Unit type flon boiled-gas-cooled rectifiers containing semiconductor devices in a sealed tank are widely used because they are so reliable, easy to maintain, nonflammable, and noiseless as to meet the needs of electric railways.
Fuji Electric has developed new rectifiers using fluorocarbon free from chlorine as a refrigerant to cope with the recent situation of international control against flon production and use.
The new product has the same basic construction as conventional one, but has been brought close to perfect one utilizing experiences in manufacturing and field operation. This paper introduces the standard specification, line-up of capacities, construction, and protection system.