TABLE OF CONTENTS It is important to begin by stressing that although readers who can absorb the material in this chapter will undoubtedly be better versed in induction motor matters than those who decide to skip it, it should be seen as a bonus in terms of the added understanding it can provide, rather than an essential.
Nothing on the equivalent circuit was included in the first two editions of the book, because it was feared that readers might Wnd it too daunting. But on reflection there are three reasons why it is logical to include such a potentially illuminating topic. Firstly, the parameters that appear in the equivalent circuit (e.g. leakage reactance, magnetising reactance) are common currency in any serious discussion of induction motors, and understanding what they mean is necessary if we wish to engage effectively with those who use the language. Secondly, a knowledge of the structure and behaviour of the circuit brings a new perspective to support the physical basis followed in the rest of the book, and in this respect it can be an excellent aide-memoire when attempting to recall aspects of motor performance. And Wnally, it provides the only simple method for quantitative performance predictions and thereby permits us to justify some of the qualitative statements made in Chapters 5 and 6.
As elsewhere in the book a knowledge of elementary circuit theory is required, together with an understanding of the material on magnetic circuits introduced in Chapter 1. In addition, readers whose basic knowledge of...
