Power Factor vs. Load Imbalance vs. Cost of Generation
Power Factor vs. Load Imbalance vs. Cost of Generation
(OP)
How would someone calculate what the savings in generation costs would be to a utility if the load imbalance on a distribution system was corrected. The thought is this will correct the low power factor to some extent.






RE: Power Factor vs. Load Imbalance vs. Cost of Generation
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
You may find some guidance at IEEE Std 739-1995 Recommended Practice for Energy Management in Industrial and Commercial Facilities a/k/a “Bronze Book,” and is available for online purchase, with sample first chapter at: www.ieee.org. ISBN: 1-5593-7696-1 Description of document at: standards.ieee.org/reading/ieee/std_public/description/colorbooks/739-1995_desc.html
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
Does not voltage imbalance cause lower Pf?
Does not load imbalance cause voltage imbalance?
If these both are true, then correcting load imbalance must correct poor Pf to some extent.
My initial question more focuses on what savings are there in the generation area when you correct the Pf .01% or more.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
No. I agree with dpc that voltage imbalance and power factor are two separate issues.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
Power factor is related to the phase angle between the voltage and current phasors. Changes in the relative phase voltage magnitudes do not impact the phase angle between voltage and current in a particular phase.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
Okay, I agree that load imbalance does not "directly" effect Pf but if load imbalance does cause voltage differences on three phase systems, how is it then that you would not agree that this consequence of the loading imbalance, 'voltage difference' does indirectly cause a lower Pf.
If one has a motor and the voltages are different between the phases and the motor must work harder, less efficient, does not this effect the power factor? Likewise, what if the voltage difference is caused by load imbalance on the feeder? Would you not then agree that poor loading equaled poor voltage which increased the current causing lower Pf.
This seems to make sense to me but I'm struggling to understand why it doesn't work the way it appears.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
You are correct that voltage imbalance on a motor does cause it to work less efficiently, but that results in additional losses (real power) in the motor. If anything, this would likely increase (improve) the power factor of the motor, rather than decrease it.
The only real savings from the generation side of the equation are the reduction of losses in the system when the power factor is improved. For the very small improvement that you have cited (0.01%), the reduction in generation due to lower system losses would be negligible.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
RE: Power Factor vs. Load Imbalance vs. Cost of Generation
Improving either/both can be used to increase system capacity, but should not be considered interchangeable.
Aside: With modern instrumentation applied at the point of common coupling, it is possible to log varying per-phase power factors, but unless extreme, the degree 'power-factor imbalance’ in itself typically represents no significant loss. Improving load balance versus power-factor correction may likely be achieved with less effort to the system of interest.
RE: Power Factor vs. Load Imbalance vs. Cost of Generation