equivalent THDv
equivalent THDv
(OP)
Hi,
I have 2 transformers on which I could measure THDv on the LV side. 1% on 1st transformer (2.5MVA), 2.1% on the second one (2MVA).
Both Transformers are supplied by the same 13.2kV switchgear
Is there an easy way to calculate the equivalent THDv on the 13.2kV side?
Thanks
I have 2 transformers on which I could measure THDv on the LV side. 1% on 1st transformer (2.5MVA), 2.1% on the second one (2MVA).
Both Transformers are supplied by the same 13.2kV switchgear
Is there an easy way to calculate the equivalent THDv on the 13.2kV side?
Thanks






RE: equivalent THDv
I assume that those two transformers have nothing more in common than the primary voltage. And that they are loaded. The load is what determines THDV to a great extent, probably around half of the THDV contribution is from the load. The only thing you can say for sure is that the 13.2 kV THDV is less than 1%
Aren't there any PT:s on the 13.2 kV side? It is an easy matter to measure there. My guess is that you wil see around .5%
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: equivalent THDv
Yes, transformers are loaded (40% for 1st one, 50% for 2nd one) and supply different gears, so as you said, nothing in commom except primary voltage. Unfortunately, no meters on the 13.2kV side....
My guess is less than 1%, but I was wondering if any calculation method (even approximation) exists.
RE: equivalent THDv
Are there predominantly non-linear loads (such as UPS, VSD, thyristor controlled heaters, Fluorescent lamps etc.)in the transformer which has 2.1% THD?
As such 2.1% at 415V is not a THD level which is a cause for any concern as the tolerable level is much higher.
RE: equivalent THDv
Bill
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"Why not the best?"
Jimmy Carter
RE: equivalent THDv
Loads are mainly motors driven by VSD.
I'm not really concerned by the value itself, as it remains under 3%.
My concern was to try to calculate the value on the 13.2kV side. But it seems clear we can't.
Thanks
RE: equivalent THDv