Page 257 - Electrical Equipment Handbook _ Troubleshooting and Maintenance

SYNCHRONOUS GENERATORS

12.20 CHAPTER TWELVE

FIGURE 12.23 (a) The speed-power curve for a typical prime
mover. (b) The resulting frequency-power curve for the generator.

FIGURE 12.24 The terminal voltage V -reactive power Q curve for a synchronous generator.
T
This plot has a drooping characteristic that is not generally linear, but most generator
voltage regulators have a feature to make this characteristic linear.
When the no-load terminal voltage set point on the voltage regulator is changed, the
curve can slide up and down.
The frequency-power and terminal voltage-reactive power characteristics play important
roles in parallel operation of synchronous generators. When a single generator is operating

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