{'fraction_non_alphanumeric': 0.017220172201722016, 'fraction_numerical': 0.0036900369003690036, 'mean_word_length': 5.074626865671642, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A time-frequency method for multiple fault detection in three-phase induction machines

It is well known that induction machine stator current is a nonstationary signal and its properties change with respect to operating conditions. The computed spectrum using the fast Fourier transform (FFT) does not provide accurate time-domain information about the operating conditions. As a result, the FFT spectrum analysis makes difficult to recognize fault conditions from the normal operation of the induction machine. A time-frequency approach is proposed in order to track some frequency components associated to electrical and load faults. This method is applied to a 18.5 kW three-phase induction machine with three broken rotor bars and under the effect of load torque variation which can result from a load fault.