Three phase vs. other polyphase systems

[sam_s.pitt]

Can anyone help me to find about advantages of three phase systems over other polyphase schemes? I know that there are advantages to switch from single phase to three phase, but why other polyphase systems like six phase or two phase are not as common?
regards.

 

[chuckey]

3 phases are good for motors, 2,4,8. . are not they all suffer from the same problems as single phase i.e. starting. 6 phase is superb for rectifying to DC, - very little ripple. BUT to isolate the supply you need a 6 pole breaker, 6 fuses. . Its just too complex other then for a very specialized industrial process.
Frank

 

[FANT]

Industry try always to save money and for this reason they try not to use more wires than the ones necessary.
To create an efficient rotating field is enough a three phase systen+m and for this reason we have it.
polyphase systems are used only to reduce the ripple on the rectified voltage and for this reason the lenght of wiring is short and hence acceptable.

Mandi

 

[e3belectrical]

Advantages of Three Phase System :

1. It is more economical as it requires less conductor material compared to a single-phase system.
2. A three-phase machine gives more output compared to a single-phase machine of the same size.
3. Three-phase motors have uniform torque, whereas most of the single-phase motors have pulsating torque.
4. Domestic power and industrial or commercial power can be supplied from the same source.
5. A three-phase motor produces more torque as compared to a single-phase motor.
6. Three-phase induction motors are self-starting, whereas single-phase motors are not self-starting.
7. Voltage regulation is better in a three-phase system.