Transient Inductance in a High-Speed Axially Laminated SynRM: Parameter Sensitivity and Its Impact on Converter Characteristics

This article presents a comprehensive investigation into the transient inductance of a 27 kW, 100 000 rpm high-speed axially laminated anisotropic synchronous reluctance machine (ALASynRM). While traditional transversally laminated rotor synchronous reluctance machines exhibit significant angular dependence of transient inductance, this study reveals and theoretically quantifies the spatial invariance of this parameter in solid-rotor ALASynRMs due to high-frequency eddy current shielding in the conductive laminate layers. A refined finite element method (FEM) modeling approach is proposed that integrates 3-D end-winding leakage effects and material resistivity sensitivity to overcome the limitations of standard 2-D magnetic analysis. This modeling framework is rigorously validated through experimental measurements on a high-speed prototype, demonstrating a maximum deviation of 6.3% and an average deviation of only 2.5%. The article establishes a novel design-oriented theoretical framework that links the machine’s transient electromagnetic behavior directly to power converter performance. By quantifying the impact of transient inductance on current ripple and total harmonic distortion (THD), a systematic methodology for selecting optimal switching frequencies and DC-link voltages is provided. This approach ensures high-performance operation while accounting for the inherent computational constraints of high-speed motor controllers.