USCG Exam PracticeMotors and generators
On a vessel's AC distribution system, the power factor is lagging due to numerous induction motor loads. Which machine, when properly adjusted, can supply leading reactive current to correct this condition?
- ✓ An overexcited synchronous motorCorrect
- B. A wound-rotor induction motor with external rotor resistance
- C. A capacitor-start single-phase induction motor
- D. A compound-wound DC motor operating as a synchronous condenser
Why A is correct
NEETS Mod. 5 §4-2 states that by adjusting its DC excitation to the overexcited condition, a synchronous motor draws leading reactive current, offsetting the lagging power factor of induction-motor loads; it may be run purely for this purpose as a synchronous condenser.
Cited:NEETS Mod. 5 §4-2