Bad Power Factor
Bad Power Factor
(OP)
We are a small/medium size utility company (60000 customers) with some customer with bad power factor(i.e.: 0.6, 0.8). What can we do to fix this other than charge them for KVAR?
Thanks in advance for your ideas!
Thanks in advance for your ideas!






RE: Bad Power Factor
RE: Bad Power Factor
1. Charge them for electrical demand (ie: bad power factor). If you have any industrial/commercial customers who run large motors this may encourage them to use their motor loads to correct the system power factor (ie: over excite their motors).
2. Install power factor correction caps (Personally I'm not a big believer in caps as they sometimes can be a greater danger than anything...especially if not 'oversized' correctly for fault/transient situations...)
3. Hook up some unloaded motors yourself to the system and overexite them (ie: synchronous condensor)
4. Hook up a SVC (static var compensator)...This is probably the most expensive, and complicated solution...however it would correct power factor and provided good voltage regulation for power factor variations.
I guess it really depends on your customers...ie: residential, commercial, industrial. For commercial and/or residential 2 and 4 would be the best options...2 being the cheapest of course. For industrial customers 1 is a good option...industrial customers typically don't like to pay too much for power so it would probably pursuade them to take matters into their own hands to correct the power factor as seen from their facility.
Like I said...even though I'm not a huge fan of caps, it's probably the cheapest and most feasable option...depending on the MVA of your load that is.
RE: Bad Power Factor
Could you please explain more of what you mean by "oversized" for fault conditions? I am familiar with possible harmonic/resonance issues and high voltage under low load conditions, but the only fault/transient issues I have heard of are outrush (which can be solved with outrush reactors) and self excitation of motors (which happens when capacitors and motors are isolated by the same protective device).
RE: Bad Power Factor
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I don't suffer from insanity. I enjoy it...
RE: Bad Power Factor
You're correct about the outrush, however, depending on the type and loacation of the fault wrt to the capacitor bank, it may experience large transient overvoltages (voltage spikes) and large voltge swings at a fast rate dV/dt ... capacitors are designed to sustain an electric field across their plates, when this is exceeded bad things happen (ie: popping and explosions)
RE: Bad Power Factor
Thanks for answer this thread. Yes it’s a star topology with two miles long feeders. We have two main loops on 69KV, nine subs. Most of our system is in the city and part of it in the county.
We do have enough caps in our 13.2Kv system to keep a decent power factor, but anyway we do have businesses with bad power factor. I’m going to list some of them:
Type of Business: Power Factor:
1) Golf Club 0.810
2) Store 0.871
3) Car wash 0.887
4) Dry Cleaners 0.682
5) Civic center 0.831
6) Apartments Office 0.822
7) Shop 0.760
As you can see they are for the most part single phase and three phase 120/240V or 120/208V commercial customers. We may need to correct on the low side beyond the meter which is on the customer side. I haven’t done this before and would like to know what can be done to address this, thanks again!
RE: Bad Power Factor
RE: Bad Power Factor
RE: Bad Power Factor
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Bad Power Factor
Sure seems like any power factor correction you need should be done at the feeder level. Use VAr controllers if you have high service voltage concerns during light load conditions.
RE: Bad Power Factor
RE: Bad Power Factor