Switched reluctance motors with segmental rotors

The magnetic design of switched reluctance motors is examined and an alternative design presented in which the rotor is made from a series of discrete segments. Single-phase machines are initially examined and design rules established. Predictions of airgap force density are presented as a function of electric loading and compared with toothed rotor equivalents. It is shown that much greater force densities are theoretically possible with the segmental design. The authors then proceed to apply the concepts developed to a three-phase configuration, which shows particular advantages. Measured test results from a three-phase machine are presented and compared with a conventional switched reluctance motor of the same dimensions, revealing both the advantages and disadvantages of the segmental rotor configuration