A three-phase thyristor rectifier is fed from a 240V (line to line) 50Hz AC source and feeds a 1512 series resistor. The initial thyristor firing angle a =80°. 

a.. Determine the maximum source inductance L for this rectifier (without the load inductance connected) if the droop in the dc output voltage at a constant full load current of 15A must be less than 8% of the peak source voltage. Show all calculations.

b. For the operating conditions of 3.e., plot the line-to-line source voltages, the rectified de output voltage and the phase-a line current for the firing angle of a = 30°.