Experimental Investigations on Flux-Linkage Characteristics and Stator-Side Modeling of a Solid-Rotor Switched Reluctance Machine

Solid-rotor switched reluctance machines (SRM), having the rotor machined from a single piece of metal, are one of the few viable options for motoring and/or generation under harsh operating conditions, including high speeds, high shaft temperature, and corrosive environment. Apart from double saliency and high degree of magnetic saturation as in any SRM, significant core losses due to high eddy currents, even under static conditions, make the characterization and modeling of solid-rotor SRM challenging. The objective of this article is to understand the magnetic characteristics of a solid-rotor SRM through extensive experimental studies and to develop a stator-side model for the machine which adequately captures its magnetic behavior. First, the flux-linkage characteristics of the solid-rotor SRM under test are measured over a wide range of excitation conditions and rotor positions. Applying a computationally efficient decomposition technique on each set of experimental data, the measured winding current is resolved into magnetizing and core-loss components to obtain a stator-side model of the machine. The proposed model is useful to predict the winding current and core-loss under different excitation conditions, which is necessary for simulation and performance prediction. The proposed method is more accurate than the existing methods, while being simple and fast to implement.