Multi layer planar concentrated windings

Planar non-overlapping concentrated windings are simple to wind and robust in operation. Since the coils may be preformed before stator construction they yield a high slot packing factor. However all the forms of the windings produce backward going fields, which can detract from their performance when used in induction machines. A novel system has recently been developed to cancel the backward going fields and produce good performance from these simple windings. Starting with this system the paper develops a number of single-sided machines using multi layered planar coils and analyzes their performance. Machines using these windings are apt for higher voltages and are efficient to construct, with savings in both labor and material costs. The winding layouts for various forms of multi layer planar machine have been outlined and the good performance of these machines has been established compared to conventional two layer windings by both 3D finite element analysis and experimental methods.