ABSTRACT
This chapter presents the basic principles that describe the behavior of alternating current (ac) machines. In particular, we will focus on the arrangement of windings, generation and spatial distribution of the magnetomotive force (mmf) in the air gap, and induction of voltage and current in ac machine windings. We will show that ac machines are essentially a combination of inductors that are magnetically coupled and whose inductances may vary with the position of the rotor. Methods for calculation of machine inductances are also presented. The foundation laid in this chapter will be helpful throughout the rest of the book where ac machines are modeled for the purposes of analysis and development of drive strategies.
