Improved two-speed single-winding single-phase induction motors

The phase symmetrization technique of obtaining a well balanced winding from a combination of unbalanced winding components, has been successfully applied to the pole amplitude modulated windings to obtain a well balanced winding for the initial as well as for the modulated poles. Methods of designing these windings using this technique are presented for a number of cases. Theoretical analysis is supported by exhaustive test results. It is concluded that this technique is useful in cases where it is desired to go from a lower pole number to a higher pole number such as 6/8, 8/10, 10/12,… etc. Copyright 1971 by The Institute of Electrical and Electronics Engineers, Inc.