This paper present the design of a permanent-magnet starter-generator unit for aerospace applications from concept to implementation. Attention is placed on the required failure-rates, system architecture, power density, prototype implementation and experimental test-setup. Measures taken to realise the failure-rates are the design of an electrical machine which can operate under unbalanced short-circuit conditions, a short-circuit detection circuit and a dedicated hardware-protection layer. An increase in power density is investigated through the implementation of an integrated magnetic component based on a novel stacked PCB approach, while a high inertia turbine simulator was realised using a back-to-back electrical machine setup.

In general, PM machines with conventional integer slot distributed winding (ISDW) schemes exhibit significant cogging torque resulting in high torque ripple which makes them unsuitable for EV applications which require low torque pulsations. This paper presents detailed analysis of the performance of PM Synchronous motor (PMSM) with fractional slot distributed winding (FSDW) scheme which shows significant reduction in torque ripple compared ISDW PM machines. Effect of the fractional slot winding distribution on electromagnetic torque pulsations has been analysed using Finite element (FE) computation technique. For a fair quantitative comparison between the above machine types, a flexible optimisation approach is proposed in this paper which generates Pareto fronts of the individual machine types.