Energy management of induction motors using non-intrusive methods

Abstract

Energy management of induction motor is relevant as they form the bulk segment in industry. The estimation of efficiency is the primary step in the energy management. Number of efficiency estimation methods were analyzed and compared and airgap torque method is found to be accurate. It was suggested to have non-intrusive methods of testing rather than intrusive methods. The paper aims to incorporate sensorless speed estimation by speed observer, resistance estimation by dc signal injection method and losses estimation according to the IEEE standards in the airgap torque method to make this nonintrusive. This method is called modified AGT method. The authenticity of this method is verified by simulations. The experiments were done on a 3 phase slip ring induction motor (3.7kW, 415V, 1430rpm, 7.5A, 50Hz).