Abstract
THIS book explains clearly the principal theorems of the theory of polyphase currents. The mathematical student who has a knowledge of French will have no difficulty in understanding it. The theorems given form an excellent basis which he can use for extending his knowledge. It will be useful, however, to make a few criticisms. When defining the instantaneous power in a circuit (p. 13) the author talks about the quantity of energy instantaneously given to the circuit. He defines also the watt current and the wattless current. The reader gets the impression that the current has more to do with the power than the electromotive force. A formal proof is given of the “equivalent” sine wave, and it is concluded that it can in general be used instead of the actual wave. Many practical engineers do make this assumption, but in some cases it will lead to very erroneous results. The so-called “equivalent “sine wave has a different area from the actual wave. The magnetic flux induced in a transformer, for example, when the two waves are applied at the primary terminals, will be different and so also will be the consequent losses in the core. The experimental method of analysing a wave is described, but we do not think that the analytical method given will be of much use. In the last chapter the theory of rotating magnetic fields is discussed in a way that will appeal strongly to the mathematician. Much of this book might with advantage be included as practical examples to illustrate the theory in a mathematical treatise on the calculus.
Théorie générate sur les courants alternatifs.
M. E.
Piernet
Par. (École d'electricité et de mécanique industrielles.) Fascicule 1. Pp. x + 100. (Paris: Gauthier-Villars et Cie, 1924.) 12 francs.
Article PDF
Rights and permissions
About this article
Cite this article
Théorie générate sur les courants alternatifs. Nature 114, 241 (1924). https://doi.org/10.1038/114241b0
Issue Date:
DOI: https://doi.org/10.1038/114241b0