D18.7 - Sensorless Control Method at Low-Speed Range using High-Frequency Voltage Injection for Synchronous Reluctance Motors Considering to Nonlinear Characteristic Due to Magnetic Saturation

Synchronous reluctance motor (SynRM) is known as a motor with large magnetic saturation. Due to the magnetic saturation effect, the dq-axes inductance fluctuates significantly, making the characteristics used to estimate magnetic pole position non-linear. This causes position estimation accuracy by the saliency based sensorless control method to deteriorate. In this paper, we firstly applied a sensorless control configuration using the high-frequency voltage injection method. Then, we have considered areas that have not conventionally been considered a lot. Specifically, we theoretically analyzed the non-linearization issue of the characteristics used to estimate the position and quantitatively evaluated them using the result of an electromagnetic field analysis. Finally, we propose the sensorless control method considering magnetic saturation and show the sensorless drive results.