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Old 08-23-14, 03:51 PM   #10
ICanHas
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Quote:
Look into the future where alternative energy is the norm and rectifier loads like PoL (Point of Load) VFDs are everywhere.
No, you're looking into the near past. As dirty load concerns grow, regulations will tighten and I expect the expansion of something similar to IEC directives in Europe regulating harmonic producing products that can be sold.

With the advent of real-time monitoring and two way communicating " embedded systems " smart meter instrumentation, it can become economical to implement firmware software based DSP digital for demand billing, harmonics or power factor penalty or auto reporting to sniff out and document source of noxious polluters without the costly task of manual investigation.

Please see the attachment to my first post. Now solution can be as easy as communicating with the customer to work out a plan.

Consider a customer engaged in unreasonable use of service such as running a roomful of bit-coin mining machines with omg so 1337 h4x PFC bypassed power supply or a multi horsepower unfiltered, minimally filtered VFD that was not meant to be used on a residential service and producing disproportionate amounts harmonics.

When power quality issues arise and that customer is unwilling to pay for his proportion of corrective equipment nor is willing to discontinuing the unreasonable use of service, the data gathered can be useful.

The history of making unreasonable levels of power line pollution could be useful in enforcing the terms of tariff "Usage of Service Detrimental to Other Customers" and seek service disconnect or seek judgment for the cost of corrective measures through the legal system.

Quote:
Originally Posted by philb View Post
Get the electric company to install a line drive reactor at the point where they occur.
Several papers are published by the IEEE. Google "vfd harmonics" I couldn't get the correct url posted here without mistakes.

If you'd like your fvd questions answered by power line engeneers, go here:
Eng-Tips Forums
http://www05.abb.com/global/scot/sco...82003d0201.pdf

Something like that is used to reduce harmonic current flow from getting past the point of common coupling. If the PoCo installs it, its coming out of rate payers. It would be the solution when harmonics at the transformer gets that bad through increased use of rectifier loads, but the idea of something like IEC directive is to prevent that from getting to critical mass in the first place.

See the attachment in this post for an example of harmonics created by one customer affecting another customer. Since the customer was not engaged in unreasonable use and the usage is not avoidable, the power company installed a separate transformer to isolate the harmed customer.

If the cause was from unreasonable use of service like the example I mentioned earlier, it would make sense to bill the offender for the cost of putting the harmed customer on another transformer.
Attached Images
File Type: pdf 2103564_6003_ENG_A_W.PDF (475.7 KB, 612 views)

Last edited by ICanHas; 08-24-14 at 12:48 AM..
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