Optimised Segmental Rotor Switched Reluctance Machines with a greater number of rotor segments than stator slots

Segmental Rotor Switched Reluctance Machines have been demonstrated to produce significantly more torque than Conventional Switched Reluctance Machines because each coil is able to link more magnetic flux. In previous work the range of topologies studied has been relatively restricted; there has been no consideration of the range of stator tooth and rotor segment number options and the designs have not been formally optimised in any way. This paper seeks to address this: using Finite Element toolsets for optimisation it describes the resulting machines - uniquely featuring a greater number of rotor segments than stator teeth. The paper assesses the credible tooth and segment options, with each option optimised to maximise torque capability. From this assessment conclusions are drawn which contrast each machine´s performance based on criteria including torque production and loss. In order to validate this optimisation process, a prototype machine is built and its performance compared with these predictions.