Identification of high frequency resistances and inductances for sensorless control of PMSM

Abstract

Recently published papers show that also a saliency in the high frequency (HF) resistances can be used for sensorless control. Those papers assume a diagonal HF resistance matrix. The aim of this paper is to show, based on experimental results, that a phenomenon like cross-saturation for the inductances is also existent for the HF resistances. The voltage drops caused by the HF resistances are typically very small and thus their identification is challenging. Therefore a high precision 3-phase current measurement is used and the dead-time and voltage drop errors caused by the inverter are compensated for. A high frequency test current control allowing zero steady-state control error is needed to overcome the limitations of voltage injection based methods.