Publication

Abstract : The aim of this work is to investigate a single broken rotor bar fault in an induction motor (IM) operating from a closed-loop speed control loop using finite element method (FEM) and to analyze the phase current data by utilizing empirical wavelet transform (EWT). Diagnosing the broken rotor bar fault at an early stage is always a major challenge in the field of induction machine fault detection. The investigation of broken rotor bar at the incipient stage becomes more complex when the IM is operated from an inverter in a closed-loop speed controlled manner due to its operation at variable speed and varying load. In this context, a 7.5 kW IM is modeled in ANSYS Maxwell with the incorporation of broken rotor bar which is coupled with ANSYS Simplorer for power supply and loading configuration. A PWM inverter with closed-loop speed control is modeled in MATLAB Simulink and co-simulated with ANSYS Simplorer to synthesize all the tools in one typical framework for realistic simulation. Then, empirical wavelet transform (EWT) in MATLAB is used to examine the phase current data obtained from ANSYS Maxwell for healthy and faulty motor. The result shows variations in the oscillatory nature of certain EWT decomposed components of line current in particular frequency bands even for a single BRB fault compared to healthy motor.