Design Considerations for Permanent Magnet Brushless Machines for Zero-Speed Sensorless Position Estimation

This paper investigates the effect of stator slot shape on the accuracy of a saliency based zero-speed sensorless position estimation technique for brushless permanent magnet machines. Three machines with different rotor topologies are used as the basis of the finite element analysis and for each machine, experimental tests are carried out to verify the accuracy of the models. It is shown that the accuracy of the sensorless position estimation is significantly affected by the shape of the stator slots