# Why HV used in HV Electric Transimision Cable

Discussion in 'General Electronics Chat' started by pandian, Feb 16, 2010.

1. ### pandian Thread Starter Active Member

Sep 27, 2009
32
0
Hi pals,

I believe HV used in electric transimision to prevent energy loss. But How is it possible?

2. ### thyristor Active Member

Dec 27, 2009
94
0
HV is used because the higher the voltage the lower the current for the same power. ie: P = V x I

The higher the current the higher the power losses in the cable which equate to I^2 x R and so would be significant.

Thus the lower one can get the current, the lower the I^2xR losses will be. And, as I said above, to lower the current one needs to increase the voltage.

3. ### myforwik New Member

Feb 15, 2010
11
0
Its pretty simple.

V = I*R
P = V*I
therefore P = I*I*R

So if you decrease the current (by increasing the voltage) the power dissipated by the resistance will be less. Which means you can transfer your energy to the load more efficienty.

Consider if your voltage is near infinite, the current will be near zero, and therefore the resistance of the line does not matter - with no current there is no power being dissipated by the transmission line.

Where as if your voltage is near zero, your current must be near infinite, causing a huge amount of power to be dissipated by the transmission line.

4. ### pandian Thread Starter Active Member

Sep 27, 2009
32
0
Thank you pals.
I've get key, I^2*R.