Page 21 - Electric Machinery Fundamentals

PREFACE

n the years since the first edition of Electric Machinery Fundamentals was
( I published, there has been rapid advance in the development of larger and more
sophisticated solid-state motor drive packages. The first edition of this book stated
that de motors were the method of choice for demanding variable-speed applica-
tions. That statement is no longer true today. Now, the system of choice for speed
control applications is most often an ac induction motor with a solid-state motor
drive. DC motors have been largely relegated to special-purpose applications
where a de power source is readily available, such as in automotive electrical
systems.
The third edition of the book was extensively restructured to reflect these
changes. The material on ac motors and generators is now covered in Chapters 3
through 6, before the material on dc machines. In addition, the dc machinery cov-
erage was reduced compared to earlier editions. This edition continues with this
same basic structure.
In addition, the former Chapter 3 on solid-state electronics has been deleted
from the fifth edition. Feedback from users has indicated that that material was too
detailed for a quick overview, and not detailed enough for a solid-state electronics
course. Since very few instructors were using this material, it has been removed
from this edition and added as a supplement on the book's website. Any instruc-
tor or student wishing to continue using the material in this chapter can freely
download it.
Learning objectives have been added to the beginning of each chapter to
enhance student leaming.
Chapter 1 provides an introduction to basic machinery concepts, and con-
cludes by applying those concepts to a linear dc machine, which is the simplest
possible example of a machine. Chapter 2 covers transformers. which are not ro-
tating machines, but which share many similar analysis techniques.
( After Chapter 2, an instructor may choose to teach either dc or ac machin-
ery first. Chapters 3 through 6 cover ac machinery, and Chapters 7 and 8 cover de
machinery. These chapter sequences have been made completely independent of