Final answer:
To find the voltage and power at the sending end of the transmission line and the voltage regulation and efficiency, we can use the short line model. Calculate the total impedance of the line using the resistance and inductance per unit length. Then, calculate the total power delivered to the load by considering the apparent power, real power, and reactive power. Finally, use the voltage and power calculations to find the voltage regulation and efficiency.
Step-by-step explanation:
To find the voltage and power at the sending end of the transmission line, we can use the short line model. First, calculate the total impedance of the line using the resistance and inductance per unit length. The resistance is given as 0.15 km and the inductance is 1.4 mH/km. So, the total impedance is 0.15 km * (1.4 mH/km) = 0.21 ohms.
Next, calculate the total power delivered to the load. The load is 300 MVA at 0.8 power factor lagging. So, the apparent power is 300 MVA, the real power is (0.8 * 300) MW, and the reactive power is sqrt((MVA^2) - (MW^2)) = sqrt((300^2) - ((0.8*300)^2)) = 240 MW.
Finally, use the voltage and power calculations to find the voltage regulation and efficiency. The voltage regulation is ((V_s - V_r) / V_s) * 100%, where V_s is the sending end voltage and V_r is the receiving end voltage. The efficiency is (real power at receiving end / real power at sending end) * 100%. Substitute the given values into the formulas to find the voltage regulation and efficiency.