DOI:10.1049/ji-2.1948.0032

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The paper gives the first comprehensive description of the complete scheme of electrification of the Southern Railway. The system of electrification is 660-volt direct current with a top-running-contact conductor rail. The return circuit is by way of the running rails. Threephase electrical energy, generated or purchased at 11,000 volts, 25 c/s, and purchased at 33,000 volts, 50 c/s, is stepped down and converted to direct current for traction, by means of rotary-convertor and mercury-arc-rectifier substations. The paper includes some historical remarks, reasons for electrification, and results. It describes the power supply arrangements, the cable transmission system, the substations, the track equipment, and the electric vehicles. Particular attention has been given to the more modern equipment, and there is some amplification of detail on matters of unusual interest. Operating features that are of interest follow descriptions of the equipment to which they relate. Construction was stopped by the outbreak of war in September, 1939. The paper deals with developments previous to that time, but the electric locomotives completed subsequently are briefly described.

DOI:10.1049/ji-2.1948.0033

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The paper is intended to serve as a guide to engineers who desire to install electrically operated lifting equipment over an area of factory, warehouse, stockyard or power plant. Emphasis is laid on performance rather than design, and mention of many of the smaller items of crane equipment has purposely been omitted. The paper discusses the information required from the purchaser by the manufacturer, and indicates the results that the purchaser may expect to get at the crane hook. A brief survey of regulations affecting the installation of cranes is given, together with some remarks on maintenance and running costs.

DOI:10.1049/ji-2.1948.0037

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The paper outlines some of the elementary statistical methods, and illustrates their application to a variety of problems encountered in the field of electricity supply.Particular attention is given to methods of describing group performance, such as by classification, and graphic representation of the frequencies at which the classified values of a variable characteristic occur, and by kindred graphs; and to the method of estimating the performance of an indefinitely large group by investigating a limited sample only. Various methods of sample selection are indicated and a number of elementary formulae added, which may enable the supply engineer to choose economic sample-sizes and to assess the significance of results. A collection of frequency diagrams illustrate conditions met with in practice. Reference is also made to the elements of correlation and regression analysis.

DOI:10.1049/ji-2.1948.0041

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The paper discusses the various factors which affect the resistance of earth electrodes and contains a summary of the different types of electrodes in common use for obtaining an earth connection. Special reference is made to the use of deep-driven rods and the results obtained by the author using these electrodes in various parts of the country.A short description is given of existing earthing practice on high-voltage apparatus, while the methods available for providing efficient protection on low-voltage apparatus are discussed in detail.The concluding Sections deal with the need for periodic testing of existing installations and the methods to be employed in carrying out such tests, with a final plea to those in authority to give a lead in a more rational approach to this most important subject.

DOI:10.1049/ji-2.1948.0042

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The calorimeter described was designed for the purpose of measuring the power loss in magnetic ring specimens under non-incremental audio-frequency excitation, with the aim of checking results of measurements by an Owen bridge under conditions involving appreciable nonlinear distortion.Reasons for the choice of calorimetric method are given, and the use of the calorimeter as a transfer instrument is considered.The use of the Owen bridge for iron-loss measurements is discussed, and results are given of measurements made on ring specimens built up of silicon-steel stampings of two different thicknesses, for values of flux density up to 10 kilogauss and of frequency up to 10 kc/s.

DOI:10.1049/ji-2.1948.0053

出版商:IEE    

年代:1948

数据来源: IET

摘要:

The paper deals with a connection for mercury-arc rectifier equipments, in which secondary windings on the interphase transformer are connected to a small auxiliary rectifying device. By this means, 24-phase waveforms are obtained from a 12-phase set, without any appreciable impairment of the other performance characteristics. The connection has been named the phase-doubled 12-phase connection. Test results and elementary theory are given. It is possible to install initially simple 12-phase equipments, and convert these to phase-doubled 12-phase operation at a later date if disturbing effects from harmonics on the a.c. side occur.

DOI:10.1049/ji-2.1948.0057

出版商:IEE    

年代:1948

数据来源: IET

摘要:

This paper shows how it is possible to use certain combinations of metal-rectifier elements, together with a dynamometer-type instrument, to indicate and measure phase angles. Full-wave or half-wave circuits, involving quite distinct principles of measurement, can be used.Formulae relating meter readings and phase angles are deduced theoretically, and practical results are compared. Provided certain compensating resistances are introduced to overcome imperfect rectifier performance, close agreement is found. The method is shown to be particularly suitable for measuring phase angles near to 90°.The application of this principle to three-phase circuits, and the effects of waveform harmonics, are also discussed.It is shown that the same principles can be used to construct a synchroscope, and tests on this type of instrument are recorded.Methods by which the phase-meter might be made to read phase angle directly are also discussed.

DOI:10.1049/ji-2.1948.0060

出版商:IEE    

年代:1948

数据来源: IET

摘要:

This paper reviews the development and present scope of British standards, published by the British Standards Institution, for insulated power cables.It is concluded that, after taking into account the wide diversity of uses for such cables, the present multiplicity of standards is not justified, and that considerable reduction of the alternative constructions now included is desirable for economical production and in the best interests of the electrical industry as a whole. Further, that some types, not hitherto included, are now sufficiently standardized to warrant their addition to the existing ranges.Very comprehensive standards are necessary and desirable in the early stages of the development of any industry. The paper suggests that the applications of electric power cables, though more diverse than at any previous time, have now reached a point at which serious and comprehensive review is justified, with the object of reducing the number of standards to a minimum compatible with modern requirements.

DOI:10.1049/ji-2.1948.0062

出版商:IEE    

年代:1948

数据来源: IET