Abstract: “The diagnosis of Induction Motors (IMs) is crucial to avoid unexpected economic losses due to their failures. To reduce the cost associated to its maintenance, a recent trend is the integration of diagnostic procedures in the electronic equipment that control the motor, such as variable speed drives (VSD)s. This paper presents a new methodology to detect rotor asymmetries and unbalanced contact resistances in IMs fed from VSDs, at standstill. The proposed approach is a non-invasive technique, can be executed on-line, and is not expensive because this method does not need extra hardware or additional sensors. Besides, the results of the proposed diagnostic method are presented in a very graphical and easy to understand way, alike to a dartboard, which makes it easily understandable by non-qualified personal maintenance. The proposed methodology is validated experimentally with a commercial induction motor with different rotors, both healthy and faulty.”

Keywords: —Induction machines, fault diagnosis, condition monitoring, motor current signature analysis, digital signal processor (DSP), field programmable gate array (FPGA), broken rotor bar