Electrical Engineering License Review, Eigth Edition
This text provides a comprehensive revew detailing all exam topics for the State Electrical Engineers exam for the Practicing Engineers license. It also contains 100+ problems and a sample exam.
TABLE OF CONTENTS Electrical Engineering License Review, Eigth Edition
Power Distribution
This chapter will include a very short review of three-phase theory with power factor correction, unbalanced loads, line faults, and a short introduction and review of three-phase transmission theory, and transformer and synchronous equivalent circuits as applicable to power transmission. Each section will begin with elementary concepts and proceed to a more advanced level. As an example, three-phase theory is well understood by most engineers and need only be skimmed over while those working "out of the area" may wish to review these relationships before exploring three-phase transmission theory. If one has difficulty with the three-phase review, he probably should skip the rest of this chapter and proceed to other areas of study.
Three-phase Review:
This discussion will start with a simplified explanation of the generation of a three-phase voltage for a synchronous generator (see Fig. 4.1) configuration. The rotor is a controllable magnetic field pole that rotates at, say, 3,600 rpm (for 60 Hz). At this point, the reader may wish to refresh his memory by reviewing the section on synchronous machines in chapter 3. The output voltage will be a balanced three-phase voltage source connected to any three-phase balanced load; and, the internal impedance of the source is approximated by the synchronous reactance, jX s, per-phase. One may imagine the source voltages as each being independent and are connected in a wye configuration with return leads. The voltages per-phase are as shown in chapter 3 (figures 3.11 and 3.12, except V T is now V P
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