none.

Electric Motors are the mostly sort device needed to drive machineries, and mostly suitable to replace combustible engines, thus, the rise in demand for electric motors in recent time. This demand has equally increased the world energy consumption, with electric machines contributing to more than 40% alone. Improving electric machine to be more functional and verse in its application will help reduce this surge in energy consumption. Proposed in this thesis is a high power density radial double stator electric machine coupled with an axial magnetic gear, and its design is based on the dual air-gap topology. Traditional electric machines have limits with regards to its size-to-power ratio, which is constrained by the bulky rotor core inherent in single air-gap electric machines. By replacing the bulky rotor and adopting the dual stator topology, this thesis is able to show that the power density of the electric machine is higher than similar topologies in the literature. Not being ignorant of the saturation effect and limited space for magnet, the rotor magnets were optimally placed so that the flux in the air-gaps is improved. The coupled magnetic gear contributed greatly in making the electric machine function as a motor and generator simultaneously due to its gear ratio feature. With this design, the motor possesses unique advantages which include, overload protection, torque fuse, high torque and low speed during motoring, and high speed and low torque during electric generation, thus making it more versatile in application.
This thesis also provides analysis of the dual air-gap electric machine using a block diagram approach, leading up to the design of the high power density electric machine. Equivalent magnetic circuit, block diagram approach and finite element analysis are some of the tools adopted in analyzing the electric machine. Also, prototypes were designed at different stages to validate the results of the numerical solutions, analytical solutions or finite element analysis. Results across these research tools are in agreement in every stage of the study.

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