Hi John:
I must admit to several motives for posting my
message regarding the WSJ-E opinion article.
1. I wanted our subscribers to know that the
issue rated comment in the WSJ-E, a high-
level, respected newspaper.
2. I wanted our subscribers to know that the
technical arguments are bolstered by some
political arguments.
As for knowing that my posting would generate
further discussion... well, that is up to our
subscribers and whether they want to move from
the technical arena to the political arena!
As for your request for comment...
> But the comment is 'non-technical' . . . can anyone in this forum offer
> any 'technical' arguments that would a)Back-up such a statement as
> Mr. Hunter's or b) FAVOR the harmonic standard?
With respect to your first question (a) I
believe you refer to Hunter's assertion that
the European electricity distributors benefit
from the standard.
I don't know that this statement is subject to
a technical argument.
With respect to your second question (b), the
technical argument in favor of the standard is
that triplen harmonic currents cause overheating
of the primary of a delta-wye distribution
transformer. Therefore, some means must be
provided to prevent such overheating.
There are several mechanisms for preventing such
overheating:
1. Use a distribution transformer with a "k-
factor" rating.
2. Use a trap (zig-zag transformer) between the
transformer and the load.
3. Require linear loads.
There may be other mechanisms. There is no
technical argument for any one of the several
mechanisms that prevent distribution
transformer overheating. Each works.
Pick one.
It is probably best to "kill" the problem at
its source.
On the other hand, it is likewise probably
best if the electricity supplier can supply
power to any load rather than restrict the
loads to which he is willing to supply power.
Because all work, the choice is subject to
other criteria. One major criterion is that
of cost:
If you are an electricity supplier, you
would not be in favor of choices 1 and 2.
If you are a product manufacturer, you
would not be in favor of choice 3.
If you are a consumer, you will pay for
choices 1 and 2 through higher electric
bills, and you will pay for choice 3
through higher product cost. No matter
the choice, you pay forever, either
through higher electric bills or for
higher product costs. If you buy lots
of products on a continuing basis, your
cost may be higher than your long-term
electric bills.
Of course, no one has shown that unacceptable
overheating will actually occur. Hence,
Hunter uses the phrase "theoretical harmonics."
Best regards,
Rich
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