Design and prototyping of an optimised axial-flux permanent-magnet synchronous machine

This study presents the design and performance analysis of a prototype axial-flux permanent-magnet (AFPM) synchronous machine. First, the design of AFPM machine is optimised by genetic algorithm based sizing equation and finite element analysis. The design objectives of this machine are maximum power density, minimum total harmonic distortion (THD) of the sinusoidal back-electromotive force (back-EMF) waveform and low cogging torque. Based on the optimised design of the machine a prototype 1 kW, three-phase, 50 Hz, four-pole AFPM synchronous machine is built. Then, the performance of the prototype machine is tested to see the cogging torque, torque-speed characteristic, efficiency and the THD of the induced voltage. It is found that the prototype machine validates the design in terms of high-power density, lowest possible THD of the back-EMF, low cogging torque while maintaining high efficiency.