Design and Analysis of PM Fractional Slot Machine Considering the Fault Operation

Electromechanical actuators for automotive chassis applications such as active/semiactive suspensions, electric power steering, and electric brakes require high-performance electric machines. This paper analyzes the practicality of fractional slot permanent-magnet electric machines for these applications based on the full investigation of five candidate machines in terms of electrical, mechanical, and also fault performances. Machine designs that simultaneously achieve high torque/ampere, high torque/inertia, low torque ripple, and fast response required for these applications are presented. Two prototype machines were built and tested and found to meet the performance requirements.