Self-sensing control of permanent-magnet synchronous machines with reluctance and saturation effects using high-frequency signal injection

This paper presents a new method for self-sensing control of permanent-magnet synchronous machines (PMSMs). High-frequency signal injection methods rely on the difference in d- and q-inductance, caused by the spatial saliency in the machine. It is shown that this effect is not only dependent on the q- but also on the d-current due to saturation effects. Therefore the robustness of self-sensing control changes over the operation range. Furthermore, errors of the widely used signal processing are discussed. Considering these challenges, a new method is proposed, expanding the operation range for self-sensing control of PMSMs.