A novel equivalent circuit involving stray load loss and harmonic torques for high speed induction motors driven by inverters

The circuit parameters involving the stray load loss and harmonic torques of high speed induction motors driven by inverters are determined by both finite element analysis and experiments. In the analysis, the parameters are directly determined from the electromagnetic field distribution of the motors under load conditions. On the other hand, in the experiment, the parameters are determined from no-load, locked rotor, and load tests. The characteristics calculated by the proposed circuits are compared with those of the measurement in order to clarify the validity and usefulness of the proposed circuit. It is clarified that the accuracy of the calculated characteristics is significantly improved by the proposed circuit as compared to the conventional circuit, particularly at high speed conditions.