PFC- Power Factor Correction & Home usage 1

[Danielt]

I'm going to through this out there for some ideas!
I worked with a sr. power supply design engineer some 20 years ago on the first pfc for a ups power supply. We had some 50 ic's. Today they have it down to one. My question is this. Is it possible to design and install a pfc at the input to my home? I want to decrease my utility bill. It's getting out of hand!!! At the time of the first pfc design the power company was craking down on large companys to correct the their usage of large amount of current they had to supply. I know they the power company was installing large line capacitors and inductors at the input to these companys to minimize the problem. One can supply huge amount of power with high enough voltage and keep the size of the wire small but you are limited to how high.

 

[jghrist]

I know of no utility that charges a power factor penalty for residential service. Power factor correction at the input to your home would not reduce losses in your home or allow use of smaller wire in the home. Therefore, the power factor correction would not reduce your power bill.

 

[Skogsgurra]

It depends a lot on where in the world you are.

I understand that you know the difference between power factor correction (PFC) and "normal" power factor compensation. What you want to do is PFC. Right?

There has been, for quite a time now, PFC units available that install before non-linear loads. Vicor have some and IC guys like Unitrode (if they still exist), Linear Technology, Maxim, Sprague and Siemens have approached the component market with controllers and application notes. IR and SGS and other semiconductor manufacturers have suitable IGBTs and diodes for this purpose.

As you probably know, The European standard EN 61 000-3-2 demands that equipment with less than 16 A consumption has a current waveform that lies within certain limits and that is why more and more computer manufacturers incorporate PFC in their power supply front ends.

 

[bgisborn]

Generally-well almost always-low power factors are caused by a heavy inductive load. In fact, that's why capacitors are used to nudge it closer to 1. If your home has electric heating, that would have no affect on the power factor and neither would any heating elements or incandensent lighting. High efficiency ballasts have power factors, at very lowest, of 0.9. Before you invest in a synchronous motor or capacitors I'd review just how often you would be using an electric motor without it's own power factor correction. Run capacitors that are found on hermetic compressor circuits are there for just that purpose-pfc. The biggest sinners of pf I've seen were large unloaded electric motors (no vfc). Not likely for a home.

 

[kh6723]

Before installing any PFC equipment, ask yourself the fundamental questions asked at the concept phase of any project .... How much is it going to cost me and how long (in this case, through the savings I make) will it take to repay the expenditure I've invested? You may find that due to the low consumption of your domestic supply it may not be economically viable to do this. In fact, if it was ... don't you think us engineers out there would have done it a long time ago !!!!

The previous writer was correct, a lot of low PF consumers are corrected at the point of usage by the equipment manufacturer. Due to the constant change in demand on a domestic supply, to get anything like a usable PFC scheme would require a reasonably sophisticated automatic control. The cost recovery period would, in all probability, simply be too great to warrant the expense.

 

[tinfoil]

I have to agree with jghrist on this one:

Danielt: I suggest to have a good look at your residential power bill. Your electrical costs are generally based on the ENERGY (measured in kilowatt-hours, or 3600 kJoule) consumed during your billing period.

I would be surprised if there is a metered peak demand (measured in kW) component to that bill.

I would be ASTONISHED if there was a metered demand component that differentiated between kW and kVA.

If your residential revenue meter is not measuring kVA, then correcting power factor will have no effect on your bill. It MIGHT have a tiny impact on your service voltage, but not enough to be of any real value.

 

[jghrist]

further to tinfoil's post:

And any effect that it does have on your service voltage will increase your bill.

 

[ozmosis]

Danielt
If, like me, you have children, invest in timers on the lights in your home! Merry Christmas