Q7.26 Do the same exercise as above with the replacement of the earlier transformer by a step-down transformer (Neglect, as before, leakage losses though this may not be a good assumption any longer because of the very high voltage transmission involved). Hence, explain why high voltage transmission is preferred?
The total resistance of the two-wire line
RMS current in the wireline
a) power loss in the line
Power supplied by plant = 800 kW + 6 kW = 806kW.
Voltage drop in the power line =
Total voltage transmitted from the plant = 300+40000=40300
as power is generated at 440V, The rating of the power plant is 440V-40300V.
We prefer high voltage transmission because power loss is a lot lesser than low voltage transmission.