DocumentCode :
1278921
Title :
The alternating-current resistance of tubular conductors
Author :
Arnold, A.H.M.
Volume :
78
Issue :
473
fYear :
1936
fDate :
5/1/1936 12:00:00 AM
Firstpage :
580
Lastpage :
596
Abstract :
Simple formulae are developed for the effective resistance to alternating currents of tubular conductors when used under the following conditions:¿ (a) Isolated conductor. (b) Single-phase system of 2 concentric conductors. (c) Single-phase system of 2 conductors of equal size laid parallel to each other. (d) Three-phase system of 3 conductors of equal size laid parallel to each other in a plane, with the middle conductor midway between the outer conductors. (e) Three-phase system of 3 conductors of equal size laid parallel to each other in triangular formation, with equal distances between conductors. In cases (a) and (b) rigid formulae are already available. The formulae developed in this paper are shown not to differ from the rigid formulae by more than a few parts in 1 000, while the reduction of labour in using the simple formulae is probably of the order of one hundredfold. In cases (c), (d), and (e), no rigid formulae are available, and the solutions put forward in this paper are the simplest and the most accurate which have yet been published. Experimental work has been undertaken to check the accuracy of the formulae and it has been found that the discrepancy between the experimental values and the calculated values is less than 3 per cent, provided that th´e ratio of diameter of conductor to spacing between axes of conductors is less than 0.85. This covers the great majority of cases occurring in practice. When the conductors are closer together than this, the errors in the formulae may be a little larger, but, even with the conductors almost touching, the greatest observed discrepancy between the experimental and calculated values of the ratio of a. c. resistance to d. c. resistance was only 6 per cent (11 per cent of the ratio of increase of resistance with a. c. to d. c. resistance).
Keywords :
conductors (electric); electric resistance;
fLanguage :
English
Journal_Title :
Electrical Engineers, Journal of the Institution of
Publisher :
iet
Type :
jour
DOI :
10.1049/jiee-1.1936.0092
Filename :
5317095
Link To Document :
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