Core loss in direct torque controlled induction motor drives: detuning and compensation

Influence of core loss on operation of vector controlled induction machines has been investigated in the past and methods for core loss compensation have been developed. A corresponding study has never been done in relation to the direct torque control (DTC). This paper discusses two aspects related to the problem of the core loss in DTC of induction machines: detuning effects and means for compensation. It is shown that the consequence of the core loss existence is operation of the motor with an output torque that can be significantly different from the torque estimate used in the control system. Using the results of the detuning study, a simple core loss compensation method is developed. The entire analysis, including verification of the proposed compensation strategy, is based on simulation.