[IEEE 2015 6th International Conference on Power Electronics Systems and Applications (PESA) - Advancement in Electric Transportation - Automotive, Vessel & Aircraft - Hong Kong, Hong Kong (2015.12.15-2015.12.17)] 2015 6th International Conference on Power Electronics Systems and Applications (PESA) - Design optimizations of outer-rotor permanent magnet synchronous machines with fractional-slot and concentrated-winding configurations in lightweight electric vehicles