power factor calculations in LV and HV metering
power factor calculations in LV and HV metering
(OP)
What calculations do you use to check total PF useing L1,L2,L3 PF readings in LV supply's and L1 and L3 in HV supply's also KW,KVA and KVArh readings are available






RE: power factor calculations in LV and HV metering
RE: power factor calculations in LV and HV metering
PF = KW/KVA.
RE: power factor calculations in LV and HV metering
RE: power factor calculations in LV and HV metering
KVARtotal = KVAR1 + KVAR2 + etc
PFcomposite = KWtotal/KVARtotal
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RE: power factor calculations in LV and HV metering
Are you being billed for low p.f. specifically or peak KVAR demand? The worst p.f. may not be occurring at peak demand times. The same logic applies to sizing p.f. correction equipment (capacitors). You'll want to know the peak KVAR.
RE: power factor calculations in LV and HV metering
RE: power factor calculations in LV and HV metering
No. See my post above. If quantities are mostly sinusoidal, you can approximate with PFcomposite = cos(atan(KWtotal/KVARtotal)).
RE: power factor calculations in LV and HV metering
I believe you mean sinusoidal PF = |cos(90-atan(kWtotal/kVARtotal))|
The 90-atan(kWtotal/kVARtotal) would be the actual phase angle. Use absolute value around the cosine because you cannot have a negative PF.
That PF formula works ok with wattless reactive power until you introduce harmonic distortions...
RE: power factor calculations in LV and HV metering
RE: power factor calculations in LV and HV metering
Yes, you are correct. What I meant to say was cos(atan(kVARtotal/kWtotal)). Pete's formula threw me off I guess. No absolute value is needed because atan returns a value in the first or fourth quadrant (depending on the sign of the argument), and cos then always returns a positive value.
galleon,
Sometimes pos/neg in inserted in front of pf to indicate leading/lagging reactive current. It is not mathematically correct, though.
RE: power factor calculations in LV and HV metering