1.1 1.2 Draw the sequence networks (indicating all the impedances) for the power system shown in Figure Q1, given that the base MVA is 80 MVA and base KV is 11kV on the zone of generator 1. Also assume that the zero-sequence of the transmission line is 3 times the positive/negative reactance. If a double line to ground fault occurs on phase "a" and "b" with an impedance, Z =j12012 occurs at bus 3, calculate: 1.2.1 the positive sequence current and voltage in pu 1.2.2 the negative sequence current and voltage in pu 1.2.3 the zero sequence current and voltage in pu 1.2.4 the fault current in pu and in KA Assume generators were operating at 2% above nominal 80 MVA, 11 kV X1=X2-j0.3pu XO-j0.075 pu 80 MVA 11/220 kV X=j0.15 pu 00000 LINE 2 LINE 1 80 MVA, 220 kV X-j0.15 pu 80 MVA, 220 kV X-j0.18 pu Figure Q1 50 MVA 11/220 kV X=j0.1 pu 00000 10.03 pu 00000 MY D 4 50 MVA, 11 kV X1=X2-j0.25 pu X0-10.055 pu (G) Koo /0.024 pu Question 2 A lamp giving out 1500 Im in all directions is suspended 12m above the working plane. Calculate the illumination at a point on the working plane 5m away from the foot of the lamp Question 3 A small light source with uniform intensity in all directions is mounted at a height of 12 meters above a horizontal surface. Two points A and B both lie on the surface with point A directly beneath the source. How far is B from A if illumination at B is only 1/12 as great as at A?