In a simple way:
Phase current=Line current
Line volage = 1.732*Phase voltage.
Line current=1.732*Phase current
Line voltage = Phae voltage
In Power systems let us say for transportation Delta is
preferable as it has 3 wires only and in distribution Star
is needed as we need Neutral also.So at the end of the
trasmission lines there will be delta/star transformer
One more thing if you consider the macines point of view
for the same line voltage copper required for star
connection is less compared to Delta as the line voltage in
Star id 1.732*phase voltage. So the winding design is to be
done to bear the 57.7% of the applied voltge which reduces
the dielectic stress and insulation resitance can be saved
interms of money.