Question

A remote small mining town in Africa with a population of some 5600 residents is supplied with
electricity from a diesel power plant with a peak demand of 5 MW.

The mine engineer has identified a possible alternative supply in the form a Run-of-River (RoR)
hydroelectric plant which would be installed in the hills some 25 km from the town.

Assume the power to the town will be transmitted via an overhead line from the Run-of-River (RoR) hydroelectric plant with the following
parameters:

R = 0.16 Ω/km;

XL = 0.24 Ω/km;

length = 25 km

Receiving end voltage 22 kV and load at pf = 0.8 lagging. Taking the receiving end voltage as the
reference phasor i.e. VR ∠ 0º, calculate

a) Sending end voltage
b) % regulation
c) Line losses
d) Transmission efficiency
e) Draw single phase phasor diagram
f) Draw a simple line diagram of the town sub-station.