Full Range High Dynamic Sensorless Control of Fractional Slot Concentrated Winding Machine

Due to their high power density, good efficiency and the resulting compactness, permanent magnet synchronous machines are one of the most used machines in traction applications. Especially for wheel hub motors with a high number of poles the fractional slot concentrated winding motor is in terms of highly automated fabrication an attractive alternative to classical motor design with integer-slot distributed-winding. The sensorless control of the machine gives the opportunity in automotive applications, where the environment is very harsh, to renounce the usage of position estimators or to use the control method as a backup. Furthermore a better high dynamic response for sudden changes like slip and slide protection can be achieved. This paper presents a high dynamic sensorless control strategy for a high pole permanent magnet synchronous machine with position estimation from standstill to full speed. For this purpose two control methods are used to cover the whole speed range. In order to accomplish a smooth transition between the two control methods, a transition procedure is proposed. The control strategy was verified experimentally on a high pole Fractional Slot Concentrating Winding Synchronous Machine and the achieved dynamics are demonstrated.