摘要:

One result of the rising standard of reliability of electrical distribution systems has been to enhance the importance of the busbars in such systems. The paper draws attention to the prevalent inadequacy of the protective arrangements of those busbars in an analysis of the character of the protection given to them as an incidental feature of the protection applied to elements other than the busbars; and contrasts this with the protection afforded by schemes specially developed for application to the busbars themselves. The desirable attributes of such specialized schemes are discussed and some of the principles employed are described and illustrated by examples. A guide to the choice of a suitable scheme for a variety of cases is given, together with some recommendations concerning supplementary measures designed to limit and localize the damage consequent on busbar faults, and to facilitate repairs.

DOI:10.1049/ji-2.1943.0045

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The paper has been written on the subject of magnetic sheet materials for electrical plant, and the nickel-iron and similar alloys used in light-current work are not specifically dealt with. The paper represents an attempt to stimulate the interest of electrical engineers and others in this class of sheet steels, in which progress in relation to the commercial materials has been relatively slow.After a short discussion of the historical development, the limitations imposed upon designers of electrical plant by the existing materials are referred to. This is followed by a brief outline of the physical basis of magnetic processes and by a discussion of the factors which affect the magnetic properties of electrical sheets. Finally, reference is made to future possibilities.

DOI:10.1049/ji-2.1943.0048

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The type of construction used for substations is generally governed by requirements, e.g. fire and air-raid precautions, which may conflict with the maintenance of the atmospheric conditions necessary for keeping the equipment in good order. These conditions are not necessarily the same as those needed for human comfort, and the application of heat alone has often been found to be ineffective and costly.The authors were faced with this difficulty and, after much investigation, evolved a method of overcoming it.Although containing a general consideration of the problem, the paper is not intended as an exhaustive treatise on the subject but merely as a record of the authors' experiences in overcoming ventilation problems in particular cases.

DOI:10.1049/ji-2.1943.0050

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The secondary power stations on the National Grid, as distinct from the main base-load stations, are usually referred to as two-shift and one-shift stations. About 80% of the stations connected to the Grid belong to the last-mentioned categories.In this paper are discussed the status and function of these stations in relation to the Grid; some running and maintenance problems brought about by Grid operation; and some of the factors affecting cost of production. Overhead costs, which in the majority of stations have not been greatly affected by Grid operation, are not considered. It is shown that by the natural process of technical evolution the number and capacity of the secondary stations will gradually increase, and it is suggested that improvements in load factor and in the shape of the national load curve will not keep pace with technical station development to an extent sufficient to alter this tendency materially.The object of the paper is to draw attention to the less spectacular but important part played by these power stations, which have taken their place on the Grid as a result of the operation of natural laws. Efficient and economic operation of the secondary stations has undoubtedly contributed in no small measure to successful Grid operation, and, although many of these stations have suffered increased operating costs and lower thermal efficiency as a result of Grid operation, the supply industry has benefited as a whole.

DOI:10.1049/ji-2.1943.0054

出版商:IEE    

年代:1943

数据来源: IET