New winding configurations for doubly salient reluctance machines

This paper develops the concept of employing a fully pitched winding in a doubly salient reluctance motor, In a conventional switched reluctance machine there is complete magnetic decoupling between phases, so that torque is produced entirely due to rate of change of winding self inductance, This effectively Limits each phase to contributing to positive torque production to a maximum of one-half of the cycle of rotation, If the same machine is wound with fully pitched windings then it can be shown that the new configuration produces torque entirely as a result of changing mutual inductance between phases, while maintaining a unipolar conduction sequence. Compared with the conventional short-pitched winding machine, far better utilization of the electric circuit results, with each phase contributing to positive torque production for at least two-thirds of the cycle of rotation, A subsequent increase in torque per unit volume inevitably results, The application of such an idea to three-phase switched reluctance motors (SRM's) is developed theoretically and through a series of experimental tests upon a 7.5 KW machine, showing static torque curves for the new machine and comparing them to a conventionally wound SRM.