What is advantage of 3 phase voltage over single phase voltage?

Answer 1

high torque compared to single phase. For the same power output the size of three phase motor will be smaller and also it will be less costly.

Answer 2

There are several advantages of three-phase motors over single phase motors. First, P = EI (Power = Voltage x Current). Three phase power is supplied to a machine shop using three wires (phases) plus a ground wire. The voltage of a single phase to ground is 110 volts (used for light bulbs, etc.). The voltage between any two phases is 220 volts (used for large heaters, etc.). The voltage when all three phases are connected to a load (large motor, etc.) is 440 volts. Therefore three-phase devices generally can develop more power. The direction of rotation of a three-phase motor can be reversed by exchanging any two of the three lead wires (either rewire the motor or use a controller to make the reversal). Three-phase motors may draw less current for a given power need allowing smaller wires in motors and and controls. Three-phase motors are usually more compact because it is almost like having three separate motors in one machine. Hope that helps a little.

Answer 3

In a three phase generator (alternator), there are three independent coils rotating together in a magnetic field, and so one machine can generate three independent voltages, unlike a single phase generator,which produces only one voltage. This saves winding costs.
A three phase four wire distribution system saves a lot of wiring when compared with a single phase system.
A three phase voltage can produce a rotating magnetic field, so that a three phase motor can run. A single phase motor requires a condenser to produce the rotating magnetic field, which can cause power limitations and also wastage of energy.

Answer 4

three phases are better than one

Answer 5

more power (watts) available

less filtering required if rectified