Four phase Electricity

I think its possible... If the generator at the generating station is made with four winding configuration instead of three winding along with suitable changes in core and phase angle between the winding, its possible to generate 4 - phase electricity but with low efficiency...

yes i seen a ppt from an friend
i asked him about this he said that that is doing in china for traction but we are not sure on place but some where it is going for traction
and when we consulted my faculty on this topic they a raised many doubts so i am not sure but i am sure it is possible

dc11see

Is it possible...to have four phase electricity?

Since for 3 phase supply the equation is following:-
Ea=E.Sinwt
Eb=E.Sin(wt+120)
Ec=E.Sin(wt+240)
So for 4 phase supply basic requirement is to be phases in such a way that they lag 90 degree like following:-
Ea=E.Sinwt
Eb=E.Sin(wt+90)
Ec=E.Sin(wt+180)
Ed=E.Sin(wt+270)

It is nice to visit my major in which I hold my bachelor's degree after a long time, thanks to this question. We also wondered then why not 2 phase or 4 phase? If somebody asks about the possibility then the answer is YES, it is possible, but the question here is why it's not used. I don't know about how to draw a diagram here in this post, so my explanation will be limited by this inability. However I hope you can imagine that, if it would have been 2 phase or 4 phase, there would be two opposing phases coming in any of these both the configurations. Now the common point of all the phases is called as neutral, which actually carries the return current. In 2 phase or 4 phase configuration (180 degrees displacement of any two phases), it is not far from imagination that when both the phases are at their peak of voltages in their cycle, the neutral will have to carry huge current for the same peak value of voltage, which is much much less in case when the phases are displaced by 120 degrees. So the size of the neutral conductor apart from other factors like I^2R losses (heat generated when current flows through a wire of resistance R with current I magnitude flows through it, and mind that the loss or heat is proportional to square of current) etc. have to be taken into consideration. In short the current in the neutral shall be least in 3 phase configuration than in 2 phase or 4 phase for the same peak voltage. As far higher phases of odd number (for example 5) the neutral current will be less but not much significant in addition to the requirement of more copper windings, so not much economical investment and unnecessary as 3 phase may provide us the necessary resolution to 1 phase where ever required. So 2 phase or 4 phase is not used. But if you ask if it may be generated, the answer is "YES".

Thanks guys...wil research this in HVDC transmission network