Comparison of resistance-based and inductance-based self-sensing control for surface permanent magnet machine using high frequency signal injection

This paper presents injection-based self-sensing (position sensorless) control methods for surface permanent magnet (SPM) machines with highly symmetric rotors. Two suitable position-dependent spatial saliency signals are compared. The two signals relate to inductance variation due to stator tooth saturation and resistance variation due to high frequency (HF) eddy current losses. Finite element analysis (FEA) is performed to investigate the properties of two saliency signals in different SPM machines. Implementation methods as well as advantages for closed-loop self-sensing control are discussed. This paper includes experimental comparative evaluation of resistance-based versus inductance-based closed-loop self-sensing control performance in a SPM machine using concentrated windings.