A Novel Current Injection-Based Online Parameter Estimation Method for PMSMs Considering Magnetic Saturation

Abstract

This paper studies the online parameter estimation of permanent magnet synchronous motor (PMSM) with the consideration of magnetic saturation and proposes a novel current injection method to estimate parameters, including winding resistances, dq-axis inductances, and rotor flux. During the current injection, the inductances will vary due to magnetic saturation, neglecting which will cause great estimation error especially in the inductance estimation. This paper proposes to use simplified equations to model the self- and cross-saturation effects during the current injection. By incorporating this saturation model into the PMSM steady-state equations, the varying dq-axis inductances due to magnetic saturation as well as the rotor flux can be accurately estimated. In addition, the estimation of winding resistance is independent of other parameters and does not get affected by the magnetic saturation. The proposed approach is validated through both the numerical and experimental studies on a laboratory interior PMSM.