DOI:10.1049/jiee-1.1928.0118

出版商:IEE    

年代:1928

数据来源: IET

摘要:

This paper describes the electrification of 170 miles of narrow-gauge railway (mostly single-track) which runs through difficult country. The electrification was designed to deal with 30000 tons of goods per day in one direction, together with a passenger traffic of about 1000 to 1500 tons.Reasons are given for choosing the 3000-volt direct-current system.The power station, transmission lines and substations are described and particulars are given of the track equipment and the locomotives.Some notes are included on operating experience since the line was put into service, and an appendix gives the names of the contractors and technical particulars of the plant installed.

DOI:10.1049/jiee-1.1928.0119

出版商:IEE    

年代:1928

数据来源: IET

摘要:

In this paper are given the results of some work which was carried out with a view to obtaining definite information as to the electrical properties of steel conductors when carrying alternating currents. The most important values measured in the tests were the “effective a.c. resistance” and “internal inductive reactance,” and it is shown that it would be impossible to calculate these in the case of iron or steel conductors.Full particulars with regard to the selected range of test samples are given, including their mechanical properties, chemical analyses and magnetic qualities.The test methods are briefly described, the method of power-factor measurement employed in the “internal inductive reactance” tests being more fully referred to in the Appendix.The effect of spacing on the values of “effective a.c. resistance” and “internal inductive reactance” is then considered. The test results show that these values do not vary with the spacing until the conductors are brought very close together and, in fact, are separated only by a thickness of paper.Some observations on the test results are given, and it is shown that the most suitable of the four grades of material tested is the “45-ton quality, hard-drawn” grade.

DOI:10.1049/jiee-1.1928.0124

出版商:IEE    

年代:1928

数据来源: IET

摘要:

In the paper an attempt is made to formulate a theory of the swaying of one span of a single overhead transmission line due to the action of a transverse wind, on the assumption that the “loop” of wire swings as a rigid whole freely suspended at its extremities.The results comprise formulæ for calculating (a) the equilibrium position of the loop in a steady wind, (b) the maximum swing of the loop due to a short gust of known intensity, as well as the rate of decay of the disturbance, and (c) the amount of continuous movement likely to be imparted to the loop by wind gusts of regular periodicity.Diagrams are given to facilitate the estimation of these quantities and a few numerical examples are worked out by way of illustration.Some suggestions for experimental investigation of swaying are made as a consequence of the form of the dynamical equations which occur in the theory.

DOI:10.1049/jiee-1.1928.0125

出版商:IEE    

年代:1928

数据来源: IET

摘要:

The difficulties experienced in connection with cable-ends when testing at high voltages in air are dealt with; and the reason for the preliminary sparking at the lead sheath and its tendency thereby to produce spark-over is explained. Various methods in normal use of overcoming this disadvantage are noted and are described in the figures. In particular, a suggestion is put forward for the use of semi-conducting material, as a temporary method of attaining greatly improved results for ordinary routine testing work. Comparative results are given both in tables and in curves, showing the advantages obtained by using semi-conducting carbon paper applied in various ways on or over the surface of the cable insulation.Theoretical lines-of-force diagrams are shown to explain these results and in what manner they are produced, and these are supported to some extent by practical measurements. Fusing-current tests are given for various samples of the material, and in view of these a possibility of the more permanent use of the principle is suggested in connection with the installation of insulators and bushings, etc.

DOI:10.1049/jiee-1.1928.0126

出版商:IEE    

年代:1928

数据来源: IET

DOI:10.1049/jiee-1.1928.0127

出版商:IEE    

年代:1928

数据来源: IET