A new windings design for improving single-phase induction motor performance

Single-phase induction (asynchronous) motors are widely used at home. These motors have two windings and usually operate at a lower performance than 3-phase asynchronous motors which have three windings. For this reason, this study aims to design a new winding of a single-phase asynchronous motor by increasing the number of phases in the motor windings in order to increase the performance of the motor. This research was focused on 36 slot capacitor-start capacitor-run asynchronous motor. The design used 4 non-identical windings in the motor, where three windings acted as auxiliary windings and one winding acted as main winding. The rated current of the designed motor winding was 2.74 A for the main winding and 3.15 A for the auxiliary winding. The performance of the designed motor compared to the traditional single-phase asynchronous motor with the same structure of stator, rotor, and rated current. A traditional single-phase asynchronous motor had data: 1 HP, 220 V, 8.3 A, 1440 RPM, 50 Hz, and 4 poles. The results of this study indicated that the designed motor operated with power factors almost close to unity and had higher output power, torque, and efficiency than the traditional single-phase asynchronous motors

High speed solid rotor permanent magnet machines: concept and design

This paper proposes a novel solid rotor topology for an Interior Permanent Magnet (IPM) machine, adopted in this case for an aircraft starter-generator design. The key challenge in the design is to satisfy two operating conditions which are: a high torque at start and a high speed at cruise. Conventional IPM topologies which are highly capable of extended field weakening are found to be limited at high speed due to structural constraints associated with the rotor material. To adopt the IPM concept for high speed operation, it is proposed to adopt a rotor constructed from semi-magnetic stainless steel, which has a higher yield strength than laminated silicon steel. To maintain minimal stress levels and also minimize the resultant eddy current losses due to the lack of laminations, different approaches are considered and studied. Finally, to achieve a better tradeoff between the structural and electromagnetic constraints, a novel slitted approach is implemented on the rotor. The proposed rotor topology is verified using electromagnetic, static structural and dynamic structural Finite Element (FE) analyses. An experiment is performed to confirm the feasibility of the proposed rotor. It is shown that the proposed solid rotor concept for an IPM fulfils the design requirements whilst satisfying the structural, thermal and magnetic limitations