Impact of Rotor Design on Sensorless Position Estimation

The impact of rotor design on the accuracy of a saliency based zero-speed sensorless position estimation technique is investigated. An existing prototype machine is used as the basis of the development and a number of possible buried magnet rotor designs are analysed before an optimal design is selected. It is shown that whilst it is possible to achieve the desired torque from a number of rotor variants, only a limited number of these are suitable for sensorless position estimation. Experimental results confirm the initial finite element based analyses