This week’s tip is also a question:
Reactive Power
Reactive power flows which way in a system supplying an overexcited synchronous motor?
A. Downstream (from generator to motor)
B. Upstream (from motor to generator)
C. Both (oscillates back and forth)
D. None of the above
The correct answer is B.
An overexcited synchronous motor acts like a capacitor and “supplies VARs (Volt Amperes Reactive)”. Thus, the synchronous motor is actually “supplying” reactive power referred to as capacitive reactive VARs. This results in a leading power factor condition in which the current leads the voltage.
Synchronous motors are sometimes used to correct bad power factor situations due to their ability to supply varying capacitive reactive power which is based on the amount of over excitation.
PdMA invites you to submit an Electric Motor Testing Tip of your own and receive a free PdMA mug or hat if they publish it! Contact Lou at lou@pdma.com.
