摘要:

The rapid growth of both industrial and domestic load in most countries since 1939 has forced the development of many water-power schemes, some of which had previously been dormant owing to marginal economies. Earlier schemes were often isolated and (with certain notable exceptions) of relative insignificance in comparison with steam-driven generating plant. With the present need for developing every practical source of power, however, the problems of controlling hydro-electric plant take on new aspects, involving consideration of uniformity and economy of operation and maintenance staffs, and the most efficient use of the catchments on each river system as a whole.After the terms used have been denned, the nature of the control problems involved are examined. Certain control schemes are described, with emphasis laid on the development of sequential-parallel automatic control and the reasons why it is preferred. Some practical aspects of the apparatus involved are described, after which the operating and maintenance requirements are examined. The electrical and hydraulic functions of group control are discussed in relation to complete river system. Finally, those factors influencing the choice of a control scheme are summarized.

DOI:10.1049/pi-1.1951.0051

出版商:IEE    

年代:1951

数据来源: IET

摘要:

The paper explains the need for high-voltage impulse generators which will produce the standard voltage waveshapes specified for impulse testing. A theoretical analysis of the impulse generator and load circuit is given, and the development of the multi-stage generator for high voltages is described. The mechanism of operation of the multi-stage generator is analysed and is illustrated by oscillograms. Illustrations of two typical generators are shown, and some of the auxiliary equipment needed is briefly mentioned. The paper concludes with an example of impulse-testing technique.

DOI:10.1049/pi-1.1951.0054

出版商:IEE    

年代:1951

数据来源: IET

摘要:

A symbolic method, using ordinary algebra throughout, is developed for the solution of some switching and relay-circuit problems. It is applied initially to 2-terminal networks consisting of switch contacts only. Each element is identified by a letter and expressions representing the networks are derived. The values 0 and 1 indicate an open circuit and a closed circuit, respectively, as applied to both a network as a whole and to individual elements; for the latter these same values also indicate whether the associated relay is unoperated or operated. A simple notation is used to distinguish between make contacts and break contacts.The method is extended to include symbols representing relay coils, and expressions are derived which represent a complete 2-terminal circuit, consisting of contacts and coils, connected to the supply battery.Problems of circuit analysis, simplification and synthesis are treated both for reflex and non-reflex types of circuit. Time effects are ignored.

DOI:10.1049/pi-1.1951.0057

出版商:IEE    

年代:1951

数据来源: IET

DOI:10.1049/pi-1.1951.0058

出版商:IEE    

年代:1951

数据来源: IET