An 8 MW and 5 MVAR three phase balanced load is connected to a three phase source with a voltage of 13.8 kV through a transmission line. The line is 20 miles in length and has a series impedance of 0.025 + j0.05 0 per mile and it is rated at 25 MVA.

a) Use PowerWorld to find the line current, load voltage and the losses in the transmission line.

b) Comment on the system and check if anything needs adjustment or if you would suggest any change; justify your response.

c) After 5 years, the load is expected to grow by 50 % (with the same power factor). Use PowerWorld to estimate the line current, load voltage and line losses at this time. Also using the simulator, find the voltage profile along the line; i.e. plot the line voltage versus the length of the line.

d) Based on these results, comment on whether the network will need improvement or it could continue without any adjustment.

e) A capacitor bank is planned to be installed after 5 years to correct the power factor of the load to 0.99. Estimate and comment on the effect of this on:

• The line current,

• The line voltage profile and compare it with the line voltage profile obtained in task (c),

• The line losses and

• The load voltage. Activate WI

f) Estimate the financial saving on losses the connection of the capacitor bank will to Settings • bring (assume £0.16 per kWh) each year. Comment on the economic feasibility of this step.