A 3-phase line delivers 1 MW at 11 kV and 0.8 lagging power factor. The series impedance of the line is 4 + j 6 ohms per phase. Calculate the sending end voltage if the load voltage is to be maintained and addition of load at the receiving end increases the line current by 50% and raises the power factor to 0.9 lagging. Also calculate the equivalent series impedance of the total load and voltage regulation.