Design of a 600kW ring-type direct-drive Flux-Switching Permanent Magnet machine for aerospace main propulsion

More-Electric flight is one of the main objectives of the aerospace industry for the future. For aerospace applications, electrical machines providing high torque density are paramount for the viability of direct-drive electrical propulsion of aircraft. Besides low-weight and high torque capability, a candidate solution should also be inherently fault tolerant for it to be used in aerospace. For these reasons a first solution based on Flux-Switching Permanent Magnet (FSPM) machines for an exemplary application of a helicopter main rotor drive was investigated, since these machines have shown high torque-to-weight ratios and high efficiency during research in the last decade. Despite this, the task of designing a machine appropriate for this application goes beyond the electromagnetic design and into the area of mechanical design much deeper than for traditional designs: The lightweight nature of such an iron-based machine makes the design of support structures and airgap control challenging and requires unconventional approaches. This paper presents the main design steps and first experimental results for such a machine.