Differential Evolution based Air-Gap Torque method approach for induction motor efficiency estimation

This paper proposes a methodology for torque and efficiency estimation of in-service induction motors based on the Air-Gap Torque (AGT) method. The proposed methodology only relies on induction motor stator voltages, currents and nameplate data. A modified stator resistance is estimated including the mechanical losses effect. This modified stator resistance is estimated by using a Differential Evolution (DE) based algorithm. The DE procedure estimates the modified stator resistance by using the stator flux equations, minimizing the torque error at the rated operation point. The estimated stator resistance is applied in the AGT method equations to compute the induction motor torque and efficiency. Simulation tests were performed to validate the proposed methodology.