Why 3 Phase Alternators are generally star-connected

Alternators are generally star-connected because of below mentioned reasons:

For same line voltage, a star-connected alternator requires less insulation compared to a delta-connected synchronous generator.
When a synchronous generator (alternator) is feeding load , the voltage per phase becomes distorted and waveform is no longer sinusoidal. The distortion primarily happens due to undesired harmonic voltage whose frequency is three times that of fundamental frequency. In case of Y Connection, the distorting line-to-neutral harmonics don’t appear between lines since they cancel out each other. As a result of this, line voltages remain sinusoidal for all load conditions. In case of delta connections, third harmonic voltages don’t cancel out, rather they add up. This is one of the reasons, 3 phase alternators are generally star connected.
In case of star connection, the phase voltage is 1/√3 times of the line voltage. Mathematically: V_ph = V_L√3. Where V_L is line voltage. Since, induced EMF in phase winding of alternator is directly proportional to number of turns, for same line voltage, less number of turns are required for star-connected alternator as compared to delta connected alternator.

So that was reason for connecting 3 Phase Alternators in star-connected configuration.