Performance Analysis of Twin-Rotor Axial Flux Permanent Magnet Synchronous Motor for In-Wheel Electric Vehicle Applications with Sensorless Optimized Vector Control Strategy

Abstract

The operating characteristics of double rotor axial flux permanent magnet synchronous motor with sensorless optimized vector control strategy is analysed in this paper for in-wheel electric vehicle applications. Double rotor single stator configuration of the axial flux motor designed using 3D finite element analysis based on a standard electric bicycle motor specifications is used for the analysis. Sensorless vector control strategy based on higher order sliding mode observer with super twisting algorithm is implemented for the performance analysis of the motor. Adoption of this method aids in the elimination of mechanical sensors from the system resulting in reduction of size and cost of the overall system which is desirable for electric vehicle application. The gains of proportional-integral speed controller in vector control strategy are optimized to reduce the speed as well as the torque ripples in the performance characteristics using particle swarm optimization algorithm. Simulation study of the sensorless motor drive system formulated on higher order sliding mode observer shows good motor performance through accurate rotor position and speed estimation which can be inferred from results. Hence the drive system is more suitable for hub motor electric drive applications.