Advantages of a three phase system

Advantages of a three phase system over a single phase system are:
• The amount of conductor material needed to transfer same amount of power is lesser for three phase system; thus it is more economical.

• Domestic power and industrial power can be distributed from the same source.

• Voltage regulation of a three phase system is quite better.

• As three phase induction motors are self-starting while single phase motors are not, so the three phase system is certainly more advantageous.

• The torque produced by a three phase motor is high.

• For a given size of the frame, three phase generator provides more output.
So,in the field of generation,transmission & distribution,use of three phase system is more economical & versatile.

That's why three phase system is preferred over a single phase system.