Short-circuit-proofed outer rotor PMSM with a wide field weakening range for high efficiency traction applications

This paper presents measured results of a high efficient outer rotor permanent magnet excited synchronous machine (PMSM) with concentrated coil windings in a single layer configuration and a fractional slot factor q of 2/5 for traction applications. Furthermore the presented non-forced air-cooled machine achieves a higher-than-average utilisation factor and field weakening range. Moreover some theory and measurements of the short-circuit strength and the reluctance torque is explained. The sensorless control capability is illustrated by measurements and statistical analysis. Also an engine characteristic curve and various data of the constructed prototype are demonstrated.