Measuring SRM profiles including radial force on a standard drives test bench

Switched reluctance machines exhibit highly nonlinear characteristics which must be known to accurately model and control this machine type. These profiles are typically derived by finite-element analysis or measured on dedicated test benches. The aim of this paper is to propose a measurement procedure that requires only standard laboratory equipment. Moreover, a method is presented that allows the reconstruction of the radial-force characteristic, which has never been mentioned before in literature. A standard current source and a differential voltage probe were used to measure flux linkage. Afterwards torque was derived from the flux-linkage profile. Radial force was reconstructed by the aid of vibration excited under particular test circumstances. At the end the three fingerprint characteristics of the machine, i.e., flux linkage, torque and radial force, are known. The results are robust against measurement noise since they are obtained by averaging numerous electrical cycles.