More than 3-phase system possible?

[samieee]

hi all,

Since there 1-phase,2-phase and 3-phase system is existing.Is it possible to have system more than 3-phases(theoretically and practically)?

I think it is possible,is my opinion correct?

 

[dlgoff]

Yes.

Higher phase numbers than three have been used. A common practice for rectifier installations and in HVDC converters is to provide six phases, with 60 degree phase spacing, to reduce harmonic generation in the AC supply system and to provide smoother direct current. Experimental high-phase-order transmission lines have been built with up to 12 phases. These allow application of Extra High Voltage (EHV) design rules at lower voltages, and would permit increased power transfer in the same transmission line corridor width.

http://en.wikipedia.org/wiki/Polyphase_system#Higher_phase_order"

 

[MThornton]

both six-phase and twelve-phase systems are not unheard of, and are utilized in some very large DC converters. Six-phase converters may use a delta-wye transformer, which provides 30 degrees of phase displacement. Zig-zag transformers provide 90 degrees phase displacment.