Contents
How does power factor change with load?
In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. Power-factor correction increases the power factor of a load, improving efficiency for the distribution system to which it is attached.
What does the power factor of an alternator depend on?
The power factor of the alternator depends upon the type of load. In case if it is an infinite bus, then the power factor of the alternator depends upon the excitation of the alternator. According to load, the alternator provides both reactive (kVAR) and real power (kW).
What is the effect on alternator if runs at leading power factor?
It is defined as the rise in voltage when a full load is removed divided by the rated terminal voltage when speed and field excitation remains the same. Voltage regulation is dependent on load current and power factor. The leading power factor reduces voltage regulation value and improves system performance.
What is the power factor of alternator at no load?
Question: What is the power factor of an alternator at no load? Answer: Power factor is the cosine of the phase angle between current and voltage. At no load current is zero, so the phase angle is 0°.
What is the impact of leading power factor?
Effects of Leading Power Factor Leading power factors can damage the power source devices such as generators, alternators, etc because generators, alternators cannot withstand the leading power factor. Leading Power causes to increase the receiving end voltage than the sending end voltage in a transmission line.
When load power factor is leading the voltage regulation is?
A leading power factor (capacitive load), the output terminal voltage will rise. Therefore positive regulation produces a voltage drop in the winding while a negative regulation produces a voltage rise in the winding.
How does zero power factor leading load affect alternator?
Zero power factor leading load. The armature reaction in alternator produces different effects such as cross magnetizing effect, demagnetizing effect, magnetizing effect. These effects cause distortion in main field flux, thereby affecting the generated emf.
How does load affect the armature reaction of an alternator?
Armature reaction is the effect of armature flux on the main field flux. The effect of Armature reaction can be seen in the DC generator as well. But compared to the DC generator, the power factor of the load in an alternator has a considerable effect on armature reaction.
How is the air gap flux of an alternator determined?
Under load, but, the air gap flux is determined by the ampere-turns of the rotor and the ampere-turns of the stator. The sequence may aid or oppose the MMF (magneto-motive force) of the rotor depending upon the power factor of the load. Leading power factors aid the rotor, and lagging power factors oppose it.
How is the phasor diagram of an alternator drawn?
The phasor diagram of an alternator for leading power factor load is shown below. For the leading power factor load, the phasor diagram is also drawn similar to that of the unity power factor. But the only difference is that here current leads the voltage by an angle Φ. So the current phasor is drawn at an angle Φ with respect to voltage phasor V.