Identification of Magnetizing Inductance for Induction Motors During Sensorless Indirect Flux-Oriented Control Under Load Conditions

Abstract

This paper proposes a method for estimating the magnetizing inductance of induction motors (IMs) and a practical inductance model for control implementation. While sensorless control techniques have been extensively studied, their performance depends on accurate parameter estimation, which is affected by magnetic flux saturation. Existing saturation models obtained under no-load conditions may not reflect the actual characteristics under load, primarily due to the influence of rotor current. To address this issue, an inductance model and its real-time identification method are proposed with an estimation method of magnetizing inductance under load conditions using indirect flux-oriented control (IFOC). The inductance model is constructed as a function of stator current which is practical to be used on microcontroller unit (MCUs). The proposed approach allows for iterative model refinement, improving accuracy across various operating points. The proposed method is validated through simulation and experiments.