Detection of rotor faults in induction motor by higher current harmonics using the matrix pencil method

Broken rotor bars in the squirrel-cage winding of an induction motor are one of the causes of premature failure in industrial equipment. A broken rotor bar leads to motor overheating, increased vibration, and reduced operational efficiency. Conventional rotor fault diagnostic methods, based on detecting fault-related frequency components near the supply harmonic in current spectra, often prove insufficiently accurate due to various masking effects, such as current signal noise, rotor design peculiarities, and changing operating conditions. The aim of the study: to apply the Matrix Pencil Method (MPM) to motor current signals to extract the amplitudes and frequencies of higher-order rotor fault harmonics near the 5th and 7th supply harmonics. These higher-order rotor fault harmonics are less susceptible to masking effects and provide more reliable indicators of rotor faults compared to components near the fundamental supply frequency.