Title :
Phase modulated 3-phase pole changing windings
Author :
Broadway, A.R.W. ; Ismail, K.S.
Author_Institution :
University of Bristol, Department of Electrical and Electronic Engineering, Bristol, UK
fDate :
3/1/1986 12:00:00 AM
Abstract :
The principle of phase modulation is described and methods of design are developed which enable 3-phase induction motors to be changed in speed using simple 6-lead switching of a single winding. The method of switching relies on special 3-parallel path connections which are derived by a novel `self paralleling¿ process. Three elemental windings are combined in such a way that the three parallel paths can be formed within a resultant single winding. The flexibility of design is more limited by comparison with the longer established method of pole-amplitude modulation, but good designs are possible for two speeds in close ratio particularly for constant-torque and constant-power duties. Examples are included together with results of tests on a trial 8/10-pole motor.
Keywords :
induction motors; machine windings; phase modulation; 3-phase pole changing windings; 8 to 10 pole motor; pole-amplitude modulation; switching; three phase induction motors;
Journal_Title :
Electric Power Applications, IEE Proceedings B
DOI :
10.1049/ip-b:19860011