A 500 kV, 50 Hz, three phase transmission line connecting two cities has a length of 260 km. The specification of the conductor is given in Table 1. The line is assumed as a lossless line. Table 1: Conductor data Conductor Name Conductor Configuration Conductor GMR Conductor Sectional Area Conductor Diameter Number of Sub-Conductors in a Bundle Bundle Spacing Distance between Phases Maximum DC Resistance at 20C ACSR Curlew Flat horizontal 0.5715 cm 591.3 mm 31.62 mm 4 45 cm 14 m 0.05518./km Based on the information given above, answer the following question. (a) Calculate the ABCD constants of the transmission line. If the values of sending and receiving end quantities can be measured and obtained, discuss how the ABCD constants of transmission line can be determined using open and short circuit condition. [10 Marks (b) The sending voltage is leading the receiving voltage by 10. If the voltage regulation of the transmission line is 5%, by using ABCD constants, determine the sending voltage and the complex power that can be delivered by the line at 475 kV. [5 Marks c) Describe briefly the operation of a lossless line under natural loading condition. Determine the surge impedance loading (SIL) of the line and suggest a method to increase the SIL value. 15 Marks A 500 kV, 50 Hz, three phase transmission line connecting two cities has a length of 260 km. The specification of the conductor is given in Table 1. The line is assumed as a lossless line. Table 1: Conductor data Conductor Name Conductor Configuration Conductor GMR Conductor Sectional Area Conductor Diameter Number of Sub-Conductors in a Bundle Bundle Spacing Distance between Phases Maximum DC Resistance at 20C ACSR Curlew Flat horizontal 0.5715 cm 591.3 mm 31.62 mm 4 45 cm 14 m 0.05518./km Based on the information given above, answer the following question. (a) Calculate the ABCD constants of the transmission line. If the values of sending and receiving end quantities can be measured and obtained, discuss how the ABCD constants of transmission line can be determined using open and short circuit condition. [10 Marks (b) The sending voltage is leading the receiving voltage by 10. If the voltage regulation of the transmission line is 5%, by using ABCD constants, determine the sending voltage and the complex power that can be delivered by the line at 475 kV. [5 Marks c) Describe briefly the operation of a lossless line under natural loading condition. Determine the surge impedance loading (SIL) of the line and suggest a method to increase the SIL value. 15 Marks