Design and predicting efficiency of highly nonlinear hollow cylinders switched reluctance motor

The conventional designs of switched reluctance motors (SRMs) with multi-rotor teeth contain some shortcomings. For example, the shaft fills a relatively high volume inside the SRM without a commensurable contribution to the output torque. In addition, the conventional toothed rotor SRM produce high torque ripples and has high iron losses compared to most electrical machines due to the switching process between the phases. These facts shaped the motivation for devising a new design of SRM. This design is intended to employ a rotor that rotates inside the stator without a shaft. In addition, the reluctance of the air gap is graded such that it produces output torque with low ripples. The new design must have a stator excited in a manner that allows the currents to pass in one direction only in each section of the stator to minimize the iron losses. This paper discusses the design steps of the new SRM that has a rotor consisting of two hollow iron cylinders and a stator excited in a way that allows a one directional current flow. The design steps are presented and estimates of the losses are presented as a means of evaluating the efficiency of the new design.