Page 235 - Electrical Equipment Handbook _ Troubleshooting and Maintenance
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SYNCHRONOUS MACHINES
11.10 CHAPTER ELEVEN
FIGURE 11.8 Synchronous motor V curves.
MACHINE LOSSES
Synchronous machine losses include the following:
Windage and Friction Loss
The friction that the gas in the air gap exerts on the rotor causes a mechanical loss known
as windage loss. Since the efficiency of a generator has a significant impact on the cost of
power generated, most units having a rating in excess of 20 MW are hydrogen-cooled to
improve the efficiency. The following are the advantages of hydrogen:
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