A fully controlled natural commuted $$3$$-phase bridge rectifier is operating with a firing angle $$\alpha = {30^0}.$$ The peak to peak voltage ripple expressed as a ratio of the peak output $$dc$$ voltage at the output of the converter bridge is

A six pulse thyristor rectifier bridge is connected to a balanced $$50Hz$$ three phase $$ac$$ source. Assuming that the $$dc$$ output current of the rectifier is constant, the lowest frequency harmonic component in the $$ac$$ source line current is

$$AC$$ to $$DC$$ circulating current dual converters are operated with the following relationship between their triggering angles $$\left( {{\alpha _1}} \right.$$ and $$\left. {{\alpha _2}} \right).$$

A thyristorised three phase fully controlled converter feeds a $$dc$$ load that draws a constant current. Then the input $$ac$$ line current to the converter has