Insulation and Design of Electrical Windings

Morris Fleming Arthur Percy

Description

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The necessity for greater attention to these problems has been forced upon engineers by the advent of high voltages and larger and more costly units. Modern scientific research has thrown much light on the electrical behaviour of dielectrics, and much scattered data has been published dealing with the properties of insulating materials. This information, however, has not been available heretofore in a co-related form whereby it can be used as a fundamental basis for the practical insulation of electrical apparatus. In this treatise the authors have endeavoured to set forth the underlying principles and methods whereby the design of insulation can be carried out with precision, and have embodied the results of many years of practical experience in connection with insulating problems.

Sujets

• Electronic engineering
• Sciences et techniques

Informations

• Publié par: Forgotten Books
• Date de parution: 27 novembre 2019
• Nombre de lectures: 0
• EAN13: 9780243632275
• Langue: English
• Poids de l'ouvrage: 6 Mo

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is ecognise tha insula ion constitu es the most vulne able pa of elec ical machine y manufacturers and use s alike conf onted wi h p oblem of how to ensure the maintenance of electrical se vice while epen ent on materials known be of an un eliable charac er The ex emely unmechanical na u e general unsuitabili y c mmercial insula ing ma e ials wi hs an ing the high tempe atu es st esses occurring in service has discou age any wi e sp e d scientific inves p ac icalof irectly iga ions application a resul he efo e insulation problems have in pas been solved largely by process of ial e o The necessi y for greate a en ion these p oblems has been fo ced upon engineers by advent of high voltages and la ge mo e costly uni s o ern scientific esea thelight on hrown much ch has elect ical behaviou o f ielect ics much sca tered da a has been published dealing with the p ope ies of insulating ma erials This info ma ion howeve has not been available heretofo e in a elate fo m whe eby can be use as a fun amental basis practical insula ion of elec ical appa a us Ifor hhave en eavoure to n his eatise authors un e lying p inciples me hods whe eby design of insulation can be ca ied with precision have embodied the esults many yea s of p actical expe ience in connec ion with insulating problems

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OFDIELECTRICS

r u ti n considering the physic l characteristics of insu lating materi s it is importan t to appreciate that all matter to some extent possesses property of electrical conducti ty and th t in t s respect the di erence between conductors and insulat rs not much one of kind as degree The exhaustive investigations Thompson and others show that the conductivity gases explained by the presence and motion infisma electrically chargedni ely particles termed ions which may be considered to consist of atoms or groups of atoms or very much smaller negatively charged particles known electrons argely a result of these investigations the electron theory has been developed which has served to throw much ight on the electrica beh viour of matter applying this theory to the study of electrical conductivity it is assumed that every atom has associated with it one or more detachable e ec rons whose aggregate negative charge is balanced by an equivalent positive charge on the atom and hat an ion possessing a deficharge is or negative ormed bnite positive y the addition of an electron to or removal from one of these neut al atoms or combinations atoms the cohesion between atoms and thei electrons is overcome the ions thus formed are ree to move under the inflanuence of elect ic force and when in motion in a definite direct on constitute what is ordinarily termed an elect ic current the magnit de of which is determined by the number of the ions and the veloci y with which they move The theory hus p esen s a mental picture of the conducting