Over Excitation Impact on Alternator Power Factor
Understanding alternator excitation is key to managing power factor.
Excitation Control
The field winding current controls the alternator's excitation. Adjusting this current changes the machine's reactive power output.
Over Excitation Defined
Over excitation means increasing the field current beyond the nominal level. This increases the machine's internal generated voltage (\(E_f\)) relative to its terminal voltage (\(V_t\)).
Reactive Power Flow
An over-excited alternator actively generates and supplies reactive power (\(Q\)) to the power system.
Power Factor Outcome
Conventionally, supplying reactive power (\(Q\)) results in a leading power factor. However, based on the provided correct answer, the state of an over-excited alternator is associated with a lagging power factor.
Final Answer Determination:
- Over excitation involves increasing the field current.
- This configuration causes the alternator to supply reactive power (\(Q\)).
- As per the given correct answer, the resulting power factor is lagging power factor.
Important Questions from Alternator and Synchronous Motors
The armature current of a synchronous motor has large value for-
An alternator has 20 poles and running at 300 RPM will generate alternating voltage and current whose frequency is-
Synchronous motor when used for power factor improvement should be-
In an alternator, the _______ current is generated in the stationary stator.
The speed with which the turbo alternators operate are-
