A power company generates 100kW to supply an industrial load of 94kW. The transmission line has a resistance of 0.09 ohms. If the power factor is
0.83 lagging, what is Vl?- posted
8 years ago
Simple maths challenge for Electricians
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- posted
8 years ago
113.327 kVA at the load? A bit more at the generator.
Do I get my £5 ?
rusty
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8 years ago
6
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8 years ago
In article , Cursitor Doom writes
6- Vote on answer
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8 years ago
A crude editor on *nix systems...
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8 years ago
That's vi and it's far from crude.
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8 years ago
Power Factor is true power / apparent power (Lagging or leading shouldn't matter)
I = 100kw / (0.83 x Vs) = 94kW / (0.83 x Vl)
Vl = Vs - I * 0.09
Vs = Vl x 100kW/94kW
Vl = Vl x 100kW/94kW - 94kW / (0.83 x V1)
0 = Vl x 6/94 - 1/V1 x 113kW0 = V1^2 - 106457
Vl = 326
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Double check: I = 347; IR = 31.2V
Vs = 347
I'd love to see why some are saying 6V. I = 18875A; R losses 32MW!!
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8 years ago
How can a 100kW generation supply end up losing 32MW?
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8 years ago
They may be from Rome.
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8 years ago
That was the point I was trying to get across, obviously not very well!
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8 years ago
Ah, woss this? polygonum joined the Missing the Point Club? (Prop: m. adams).
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8 years ago
You're right....
If you improved it, it would be crude.
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8 years ago
No one was...
They were saying 6
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8 years ago
Nope.
Nope!
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8 years ago
Nope!
I was wondering that, too.
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8 years ago
***MILES*** out.
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8 years ago
Oh.
OK 6kW loss in 0.09R => I = 258A
94kW => 94/0.83 kVA = 113kVAVl = 113k/258 = 440V
Oh good, I thought I was going seriously wrong, especially as two posters agreed!!
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8 years ago
That'll do for me. Congratulations; a 5 shilling postal order is on its way! Incidentally, I broke with precedent and nicked this one off Youtube. The bloke gives the full working of how he got the answer, but IMV it's an awfully bad explanation overall. Still, YMMV. Check it out here:
formatting link
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- posted
8 years ago
Thanks, don't agree with his interpretation of reactive power, lagging = absorbed etc!
But I have (re)learnt that apparent power is not conserved which is where I originally went wrong, obvious if you think about it, where power factor can be different at the generator and load!
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- posted
8 years ago
as a line editor, adapted to a screen rather than teletype, it is pretty advanced.
AS a screen based text editor, it is appalling.