Hi John:
> >Of course, no one has shown that unacceptable
> >overheating will actually occur.
>
> Do you have any more such gems to contribute? What do you think happens
> to the total current through a capacitor when the applied voltage
> contains harmonics? What happens to the I^2R loss and the dielectric
> loss? What happens to hysteresis loss in motors and transformers?
My assertion is based on the original reason for the
harmonic current emission standard, not the general
case for problems caused by harmonic currents. I
apologize for writing in such a way as to confuse the
general case of overheating due to harmonic currents
with the specific case of overheating in distribution
transformers.
My recollection of the original reason for the
harmonic current standard was to prevent overheating
of distribution transformers on the public power
network.
Perhaps you can correct this recollection. If this
is not correct, then kindly disregard the following
remarks.
Based on my probably incorrect recollection, my
assertion is that no distribution transformer in the
public power network has failed due to harmonic
current.
I further recall that such failures were a prediction
based on the expected proliferation of products with
full-wave rectifiers, especially SMPS. The electric
power distribution representatives to the committee
predicted massive distribution transformer failures
due to harmonic currents by the year 2000 or
thereabouts. Therefore, the committee operated with
a high sense of urgency.
Perhaps you can correct me on this recollection.
Can you tell us whether, at the time the work on the
standard was initiated, any such transformers had
indeed failed due to harmonic current overheating?
Or, have any such transformers failed due to harmonic
current since the work has been undertaken?
Best regards,
Rich
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