- 1 A A 66 Kv Three Phase Star Connected Short Transmission Line Has A Per Phase Impedance Of 5 J5 02 If The Line 1 (34.21 KiB) Viewed 39 times
- 1 A A 66 Kv Three Phase Star Connected Short Transmission Line Has A Per Phase Impedance Of 5 J5 02 If The Line 2 (36.48 KiB) Viewed 39 times
- 1 A A 66 Kv Three Phase Star Connected Short Transmission Line Has A Per Phase Impedance Of 5 J5 02 If The Line 3 (54 KiB) Viewed 39 times
- 1 A A 66 Kv Three Phase Star Connected Short Transmission Line Has A Per Phase Impedance Of 5 J5 02 If The Line 4 (23.72 KiB) Viewed 39 times
2 A factory having a maximum load of 800 kVA at 0.6 power factor lagging and the load factor is 0.7. The factory is charged with two-part tariff. Given: Maximum demand charge = $80/KVA/annum Energy charge = $0.15 /kWh Capacitor bank charge = $240/kVAr Capacitor bank's interest and depreciation per annum = 10% The factory works 12 hours a day and 200 days a year. Determine: Ref. PC-2 (a) the most economical power factor of the factory; (b) (c) Answers (5 marks) the annual electricity charge when the factory is operating at the most economical power factor; and the annual cost saving. (6 marks) (9 marks) Marks
3 Referring to the below figure, a symmetrical three-phase short circuit fault occurs at Point F. The parameters of the equipment are shown below. (b) Using 100 MVA as the base MVA, determine: Ref. PC-3 (a) (c) (d) (e) (f) (8) (h) (i) Generator (G): 11 kV, 50 MVA, 15% Transformer 1 (T1): 11/132 kV, 10 MVA, 10% Transformer 2 (T2): 11/132 kV, 10 MVA, 5% (j) tot the per unit impedance of Generator (G); the per unit impedance of Transformer (T1); the per unit impedance of Transformer (T2); the per unit equivalent impedance of the system; the fault level in per unit value; the fault level in the unit MVA; the fault current in the unit Ampere; (2 marks) (2 marks) (2 marks) (2 marks) (2 marks) (2 marks) (2 marks) the reactance of the reactor in per unit value if a reactor is added in between the generator G and the 11 kV busbar so that the fault level is limited to 50 MVA; (2 marks) the base impedance (Zb) at the 11 kV busbar; and (2 marks) the reactance of the reactor in Ohms (0) if a reactor is added in between the generator G and the 11 kV busbar so that the fault level is limited to 50 MVA. (2marks)
4 A delta/star connected 132 kV/11 kV 150 MVA Power Transformer (PT) is equipped with a differential protection scheme. The Current Transformers (CT) having a ratio of P:5 are installed at the HV side of the PT while the CTs having a ratio of 1,000:5 are installed at the LV side of the PT. Determine P. (20 marks) Ref. PD-4 Answers Marks