Comparative study of different rotary position sensors for electrical machines used in an hybrid electric vehicle application

A key parameter to perform an accurate and efficient control of an electric machine is the position sensor. The sensor measures the angular position of the rotor shaft and there are several ways and techniques to do this. This thesis aims to compare different position sensors with main focus on the resolver and Hall-effect sensor and other ”new” sensor techniques. Various enhancement methods to improve the position information and prediction are also evaluated. The results shows on best performance considering the torque quality when using the resolver as position sensor. The Hall-effect sensor can be improved with a observer, but the observer is not suitable for this type of application. The Hall-effect sensor has also a speed depended torque ripple that leads to harmonics at frequencies that relates to the speed of the unit which may causes problems. There are several ”new” sensor techniques based on the theory of eddy-current that may be of interest since they are said to be more optimized ∗Many thanks to Jonas Ottosson (BorgWarner), Gustaf Lagunoff (BorgWarner), Francisco Marquez (IEA) for Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) applications.