A village with a demand of 800 kW electric power at 220 V is located 30 km from an electric plant generating power at 440 V. The resistance of the two wire line carrying power is 0.25 `Omega`/km. The village gets power from the line through a 4000 V – 220 V step down transformer at a sub-station in the village. Assume negligible power loss in the transformers
(a) Estimate the power loss in form of heat in the transmission line.
(b) How much power must the plant supply?
(c) What is the input and output voltage of step-up transformer at the plant ?
(d) What difference will it make if the village receives power through a 40,000 V – 220 V step down transformer

Answer

`(a)600kW (b)1400kW`
`(c ) 440V-7000V`(d) `"line power loss will drop to 6kW .power supply needed from plant=806kW"`