A three-phase voltage source with a terminal voltage of 22kV is connected to a three-phase transformer rated 5MVA 22kV/220V. The transformer has a per-phase series impedance of 0.05 pu and is connected to a distribution line with series impedance of 0.01+0.05Ω per phase. The line supplies a balanced three-phase load rated 1MVA, 220V with 0.8 lagging power factor.
a. Draw the one-line diagram of the system described.
b. Draw the equivalent per phase circuit of the system indicating all impedances in per unit. Use 1MVA, 220V as the base at the load.
c. Calculate the real losses in the transmission line in kW.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w