Alternating Current Motors (Classic Reprint) - Couverture souple

Sedgwick, Catharine Maria

Couverture souple

ISBN 10 : 1330449746 ISBN 13 : 9781330449745

Editeur : Forgotten Books, 2018

Synopsis

Learn the principles behind alternating current motors and how they behave in real machines. This edition explains how induction motors generate revolving fields, how excitation affects performance, and how to analyze current, torque, and efficiency with practical diagrams and equations.

With clear explanations of single- and polyphase configurations, the book builds from core concepts to more advanced topics like synchronous converters, motor starting methods, and the interaction between transformer fields and speed. It emphasizes reliable methods and cautions against overextending empirical formulas beyond tested ranges.

• How induction motors produce torque, and how design choices influence performance


• The revolving and speed-field concepts that describe motor action at different speeds


• Excitation methods, including single-phase and polyphase approaches, and their impact on currents and losses


• Applications to synchronous converters and related rotating machines, with practical measurements and analysis

Ideal for engineers, students, and technicians seeking a solid, application‑oriented understanding of alternating current motors.

A propos du livre

Présentation de l'éditeur

Moreover, the significance of each transformation is carefully explained, so that the reader may be constantly reminded of the fact that he is dealing directly with electromagnetic phenomena and only indirectly with mathematics. It has been assumed that the reader is familiar with the fundamental facts of electricity and magnetism, and that he has some knowledge of the lower branches of mathematics. No attempt has been made to explain the manner in which alternating electromotive forces and currents may be represented in value and time-phase position by straight lines, because a knowledge of such representation can be presupposed. Much attention is given to graphical diagrams and to examination of the facts upon which they are based. Where necessary the errors involved in the assumptions are pointed out, and the magnitude of their effect on the final results are discussed. In developing the graphical diagram of the induction motor, the proof that the current locus is (approximately) a circle has been based on the relation between the equivalent electric circuits considered as certain interconnected resistances and reactances, rather than on the resolution of the magnetic flux into certain components. The latter method is the one most commonly employed. It is believed, however, that the former method possesses peculiar advantages in permitting the reader to follow the development step by step without losing sight of the involved electromagnetic relations, and in allowing the inaccuracies in the assumptions to be definitely determined. The major portion of the volume has appeared as articles in various publications, notably the Electrical World, the American Electrician and the Sibley Journal of Engineering. The writers thanks are due to the editors of these publications for permission to incorporate the articles in this book. The writer wishes to take this op
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Présentation de l'éditeur

Excerpt from Alternating Current Motors

A comparison of the present edition with the second edition of this book will show that the essential features of the recently developed "split-pole" variable-ratio synchronous converter are discussed in the simplest possible terms, there has been added a chapter on "Synchronous Motors," in which all of the characteristics of this machine both as a motor and as a "condenser" are fully treated, and the chapter on the "Prevention of Sparking in Single-Phase Commutators Motors" has been expanded to include the recent improvements in commutating-pole motors. Throughout the whole book an effort has been made to distinguish between "electrical-time" degrees "electrical space" degrees and "mechanical-space" degrees. The importance of making such a distinction will be appreciated when one considers the uncertainty and confusion that must be produced in the mind of a person unfamiliar with the facts when he is told that in a certain multipolar machine two fluxes are "in quadrature." The fact that many writers do not distinguish between the three different angles has caused the author to lay particular emphasis on these distinctions, in order to remove any confusion that may already exist in the mind of the reader.

The book has been written and revised exclusively for the reader, - and the particular reader for whom the book is intended is assumed to possess a fair general idea of electromagnetic phenomena and wishes to acquire specific information concerning the various types of alternating-current motors. In selecting the methods of presentation, choice has been made of the treatments which serve to impart the maximum of information with the minimum of confusion. As one reviewer has aptly stated, "The general method of treating all motors is first to outline the theory roughly, leaving out the less important factors, and then to go through again putting in the details."

Détails de l'édition

• Éditeur: Forgotten Books
• Date d'édition: 2018
• Langue: anglais
• ISBN 10: 1330449746
• ISBN 13: 9781330449745
• Reliure: Broché
• Nombre de pages: 340
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