Why is H.V used for the transfer of electricity from power plants?

Electricity is transmitted on HV to reduce transmission losses; which is proportional to square of current.
Current is inversely proportional to voltage; the higher the voltage lower will be current.
In return lower current will result in lower power loss.
Similarly less current flow will help to reduce the conductor size and make it economical.

After power generation step up transformer use it step up voltage level 11kv or 25kv to 220kv or 500kv because increase the voltages to reduce the power loss Ploss=Squre of current * conductor resistance =(P/V)2* r

we use high voltage for power transmission because: 1-reduce the crose section of cable (cable size) .

2- reduce the power losses.

3- reduce the cost .
4-easy to use step-down transformers at destination.

for the specific MW, at high voltage, current is low..... at low current we need conductor of Small dia ultimately economical it is.

 

Because there is no other way to transmitt bulk of power to remote areas.

To reduce power losses coz P(losses)=IR and when we increase the volt the current will be decreased (Ohm Law) and this cause reducing in power losses

reduces heat losses, ie I square losses.
H=I^2 R, as voltage increases, current reduces in a step up transformer thus reducing the current and hence the losses.

to reduce power loss

to reduce cost

To reduce the line losses i2r losses.
voltage is stepped up and current reduced decreasing the line losses

Electricity deliver from power plant have big capacity shall use H.V because to reduce losses in cable transmission.

To decrease current.....................

decrease losses........................

decrease conductor material....................

decrease size of poles................................

in short decrease cost......................