An Empirical Mode Decomposition Approach for Multiple Broken Rotor Bars Detection in Three-Phase Induction Motors at No-Load Condition

This paper presents an empirical mode decomposition (EMD) approach for multiple broken rotor bars detection in squirrel cage induction motors running at no-load condition, using the resultant magnetic flux density measured by a Hall Effect sensor installed between two stator slots of the electrical machine. Usually, the traditional motor current signature analysis (MCSA) has produced many cases of false indications related to, among other reasons, incorrect speed estimation, operation at low load (low slip) and nonadjacent broken bars. This study has investigated the application of the EMD technique in the signal collected from the Hall sensor, in order to detect broken rotor bars for an induction motor running at very low slip and subjected to adjacent and nonadjacent broken bars. The present approach has been validated from some experiments carried out by a 7.5 kW induction motor fed by a sinusoidal power supply in the laboratory.