SHATAKSHI

• Sep 2nd, 2011

 

Taking ex from 3 phase motor, in distributed windings, the windings are displaced by 120 degree physically as well as in phase. This gives rise to rotating magnetic field.

Taking ex from transformer, windings are displaced at 120 degree only in phase. It gives rise to pulsating field.

bittu123

 Profile Answers by bittu123 Questions by bittu123

• Nov 7th, 2011

 

@above,
You may be trying to answer"Why 3-ph winding in rotating machine gives rotating field but same 3-ph winding in transformer does not?"... B'coz, rotating machine's winding is 120 degree spatially displaced whle transformer's winding are not.

But lemme explain What is exactly distributed and concentrated winding? Both of these terms is related to rotating machine.

CONCENTRATED WINDING: As name suggest,all conductor are concentrated in one slot under a pole. if there is only one slot available for winding under one pole. In very short, if slot = no. of pole,called concentrated winding.

DISTRIBUTED WINDING: if no. of slot is more than no. of pole. means, winding is distributed in many slot under a pole.

DIFFERENCES BET CONCENTRATED AND DISTRIBUTED WINDING......
1. Induced emf in concentrated winding is greater than distributed.(But why? explain later)
2. harmonic or noise in distributed winding is lesser than concentrated winding.(that's why we normally use distributed winding in expense of lesser emf).So, improved waveform
3.less armature reaction in distributed winding.


WHY INDUCED EMF IN CONCENTRATED WINDING IS MORE?
-Just assume, there are 4 conductors and emf induced in conductor which is just below pole is 2v. Since in CONCENTRATED WINDING all conductors in single slot which is just below pole. So, total emf, Ec=2+2+2+2=8v.

-But in DISTRIBUTED WINDING,only one conductor will be just below pole, So emf induced in this conductor=2v, but other conductor will be in different slot which must be displaced from pole, let angular displacement of this from pole is ß1. induced emf in this conductor will be 2*sinß1..... and so on.
finally, In this case, total emf, Ed=(2+2*sinß1+2*sinß2+2*sinß3)

Hmmmmmm, Since sinß<1,So, Ed

Ravikumar Eta

• Jan 10th, 2016

 

In concentrated type winding, all the winding turns are wound together in series to form one multi coil.

In distributed type winding, all the winding turns are arranged in several full pitch or fractional pitch.

karthik

• Jan 20th, 2016

 

Concentrated and Distributed wiring definitions