Differences between series and parallel connection in machines with asymmetric magnetic circuits

In conventional machines, the assumption of cylindrical symmetry simplifies theoretical considerations considerably and leads to the belief that there is no essential difference between the operation of an a.c. machine in which all the coils of each phase of the primary winding are connected in series and one in which they are in parallel. The paper shows that such an assumption is not valid for machines with asymmetric magnetic circuits. Linear motors are used to emphasise the phenomena discussed, since the degree of asymmetry in such machines is very large. Methods of end-grading of windings are derived.