In a three-phase half wave rectifier usually, the primary side of the transformer is delta connected because

A)
it has no neutral connection
B)
it provides a path for the triplen harmonics
C)
we can get greater output voltage
D)
it provides better temperature stability

Correct Answer : Option (B) :   it provides a path for the triplen harmonics


Explanation : The delta connected winding help circulating and eliminating the triplen (3rd order) harmonics.