Effects of asymmetry in far fields of permanent magnet motors

Summary form only given. Permanent magnet machines are being considered for use in electric ships as pumps and drives. The exterior fields of these machines are of concern. These fields decay at a rate that depends on the number of poles, fields from higher number of poles decaying more rapidly. If there is an imbalance in the set of poles, the lower order decay of the unbalanced poles dominate in the far field and the advantage of using a high number of poles could be lost.