Using Motor Current Analysis for Broken Rotor Bar Fault Detection in Rotary Machines

Three-phase induction motors are considered the backbone of the modern industrial processes. Incipient stage detection of deformities in induction motors is very essential to prevent them from catastrophic failures. The detection and diagnosis of broken rotor bar fault has been receiving prominence amid modern industrial era. An irregularity in operation of motor produces harmonic content in motor supply current. Thus, motor current analysis can provide requisite useful information about occurrence of machine faults in near future. In this paper, a comparative analysis of broken rotor bar fault diagnosis is carried out under different motor loading conditions and fault severity. The detection of fault related components is done with the help of steady state current analysis using Fast Fourier Transformation (FFT). This method is load dependent and capable of identifying the fault using magnitude of frequencies in current spectra.