Page 25 - Electrical Equipment Handbook _ Troubleshooting and Maintenance
P. 25
FUNDAMENTALS OF ELECTRIC SYSTEMS
1.24 CHAPTER ONE
FIGURE 1.30 Voltage phases for Y connection.
FIGURE 1.31 Current phasors for connection.
Figure 1.32 illustrates a graphical representation of the instantaneous power in a three-
phase system. It is clear that the instantaneous power is constant and equal to 3 times the
average power. This is an important feature for three-phase motors because the constant
instantaneous power eliminates torque pulsations and resulting vibrations.
REFERENCES
1. D. Halliday and R. Resnick, Physics, Part Two, 3d ed., Wiley, Hoboken, N.J., 1978.
2. A. S. Nasar, Handbook of Electric Machines, McGraw-Hill, New York, 1987.
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
