Adaptive flux observer with on-line inductance estimation of an interior permanent-magnet synchronous machine considering magnetic saturation

This paper presents an adaptive flux observer to estimate the stator flux linkage and stator inductances of an interior permanent-magnet synchronous machine considering magnetic saturation. This work adopts the concept of static inductance and dynamic inductance in the machine model to describe the relationship between current and flux linkage and between their derivatives with respect to time. The flux observer is designed in the stationary reference frame and the static inductances are estimated by using the estimation error in the rotor reference frame. Lyapunov-based analysis is given to discuss the stability of the proposed adaptive algorithm. The dynamic inductances are estimated from the estimated static inductances using Taylor expansion. The simulation and experimental results show the feasibility and performance of the proposed technique.