How Do You Calculate Power Loss in High-Voltage Transmission Lines?

[mlsohani]

Homework Statement

A high-voltage transmission line with a resistance of 0.345 ohms /km carries a current of 1.05 kA. The line is at a potential of 600 kV at the power station and carries the current to a city located 173 km from the power station.
A>What is the power loss due to resistance in the line?
B>What fraction of the transmitted power does this loss represent?

Homework Equations

P=IV
p=V^2(R)

The Attempt at a Solution

part A>I used the kilometers to figure out the resistance from the distance. I then tried pluging in the values into the equations but the answer is not working.

partB> In order to calculate the fraction I want to make sure I am setting hte first part of the equation correctly. But I assume that you subtract the power loss from the original power.

 

[RoryP]

your second equation is wrong, its P=(V^2)/R
maybe that might help?
also could you tell me the answer to see if i got it right =]
cheers

 

[mlsohani]

OK I keep getting it wrong

so I now tried: P=I^2*R

I did 0.345ohms/km * 173 km= 59.685

Then I did P=I^2*R to get> (1.05kA*1.05kA)*(59.685ohms)= 65.8 kW

BUT it keeps telling me I am WRONG! PLease help!

 

[ImAnEngineer]

I did 0.345ohms/km * 173 km= 59.685

P = I² *R = (1.05kA*1.05kA)*(59.685ohms)= 65.8 kW

You might want to plug that into your calculator again :P

(1,05 * 10³)² * 0.345 * 173 = 65.8 MWIs that the correct answer? (sounds like a little too much to me but I don't know...)