EIT Electrical Review, Second Edition
Written for the FE/EIT Electrical Exam, this volume provides a complete review of all exam topics, including end-of-chapter mini exams with complete step-by-step solutions.
TABLE OF CONTENTS EIT Electrical Review, Second Edition
Chapter 4: AC Machines
Overview
This chapter on ac machines will review transformer equivalent circuits, three-phase synchronous motors/generators, and induction motors, also included is a very short introduction to single-phase machines. It will start with transformer equivalent circuits; ac motors and transformers have similar equivalent circuits. Yes, a transformer is considered a machine!
Although some mention will be made of single-phase machines, they are somewhat more difficult to analyze. However, without getting into too much detail, the speeds are fairly easy to find if one knows the slip; this quantity will be discussed.
For additional review reference material, almost any machinery type text (even though 20 or 30 years old) will be suitable. One text that is widely available and has had a number of editions is by Fitzgerald [1], Kingsley, and Kusko, ELECTRICAL MACHINERY, McGraw-Hill, any edition.
[1]Fitzgerald, Kingsley, and Kusko, ELECTRICAL MACHINERY, McGraw-Hill, any edition.(Earlier editions are without Kusko.)
Transformers:
Since transformers transfer energy through a changing magnetic field and back again, they fit into the machinery category. From the ideal lossless transformer as in Chapter 1 (see Fig. 1.3), it is easy to show that a load, Z L, on the secondary side, is seen on the primary side as 
. Then the transformer equivalent circuit that takes into account the resistance and inductance of the primary windings as R 1 and X 1 in series with the referred secondary a 2 R 2 and a 2 X 2 is as shown in...
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