# zero power factor method of alternator for pre determining voltage regulatation

Discussion in 'General Electronics Chat' started by MKY, Apr 5, 2015.

1. ### MKY Thread Starter New Member

Feb 18, 2015
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why should we go for zero power factor in this method for pre determining voltage regulation?why should it be a purely inductive load(with zero pf lagging)..can we have purely capacitive load for this test?(zero pf leading)?what happens if we use other than this zero pf load??what are the advantages using zpf load instead of other loads?

2. ### Papabravo Expert

Feb 24, 2006
10,180
1,800
I think you are confused. Power factor is the cosine of the angle between the current and the voltage. When the current and the voltage are in phase the angle between them is 0°, and the cosine of 0° is, as you know, one. Voltage will lead the current for an inductive load, and the reverse for a capacitive load. The cosine of +90° is the same as the cosine of -90° namely 0. So zero power factor is not a unique description of what is going on. It could be either. Since it lacks the element of precision it is kind of an ambiguous description. To resolve the ambiguity one of the two conditions might be chosen. From an industrial perspective an inductive load is many times more likely that a capacitive load.

3. ### MKY Thread Starter New Member

Feb 18, 2015
12
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do you mean to say that ...as we have no capacitive loads in practical...we are using inductive loads ...am i correct sir?

4. ### dl324 Distinguished Member

Mar 30, 2015
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626
As Papabravo mentioned, you have it backwards. A power factor of 1 is most desireable. Mainly it helps power companies and they give customers better rates if they can correct the power factor on their equipment.

5. ### Papabravo Expert

Feb 24, 2006
10,180
1,800
Read carefully what I said. The term "zero power factor" is ambiguous. It occurs when we have a load that is an ideal inductor. It also occurs when we have a load that is an ideal capacitor. If we are going to pick one of those two conditions, I would pick the inductor because in practice it is more likely. A real inductive load, like a motor, will actually present a range of possible power factors from cold start, to spinning up, to running at steady state.

What does power factor have to do with alternators and voltage regulation. As far as I know it is a complete don't care.

6. ### WBahn Moderator

Mar 31, 2012
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4,808
It might help if you describe what "this method" is that you are talking about? Presumably you are talking about something called the "zero power factor method". Okay. So what IS the zero power factor method? Also, what do you mean by "pre determining voltage regulation"?

We are not mind readers and few of us have crystal balls that are still in calibration.