The seventh edition of Electric Machinery was developed recognizing that the strength of this classic textbook since the first edition has been its emphasis on building an understanding of the fundamental physical principles underlying the performance of electric machines. Much has changed over the years since the publication of the first edition due to the development of new grades of electrical steel, new insulation materials, superior permanent-magnet materials, the introduction of power-electronic drives and controls, and the widespread availability of computers and numerical software which greatly increases the capability to apply analytical techniques to the analysis of electric machines. Yet the basic physical principles remain the same and this seventh edition is intended to retain the focus on these principles in the context of today’s technology.