GB1098075A - Improvements in or relating to rotary electric machines - Google Patents

Abstract

1,098,075. Winding layouts for dynamoelectric machines. MAWDSLEY'S Ltd. Oct. 5, 1964 [July 19, 1963], No. 28788/63. Heading H2A. A machine whose stator windings can be re-connected to simulate machines differing in pole-number, coil-pitch, coil-grouping and coil connection, comprises two double-layer windings wound in the same slots, both ends of every coil of both windings being brought out to external terminals. In the simplest form of the invention, Fig. 1, two identical windings A, B, each of two-thirds pitch with respect to two poles, are used. The upper winding A simulates the M.M.F. produced by the upper layer conductors of a two-layer winding, while the lower winding B which is connected to carry reverse current, simulates the lower layer conductors of a two layer winding. Hence by selective connection of the windings, different coil-pitches of the whole winding can be simulated. By omitting coils, the effect of different, e.g. fractional, numbers of coils per pole per phase may be simulated. By relying on harmonics, higher pole-numbers may be simulated. In the two-thirds pitch winding shown, third harmonics are eliminated, but by suitable connections various higher pole-numbers not a multiple of three may be obtained. Polenumbers which are a multiple of three may be obtained by windings producing odd harmonics, e.g. having half-pitch or full-pitch coils. If desired, the two windings may be of different pitch.