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2. Literature review
I. Hussain and et al proposed fault detection and identification system of a three-phase
induction motor by using signal processing techniques of STFT using MATLAB/Simulink. In
their study, they proposed fault detection of an Imbalance of supply voltage, a single phase of
supply, and broken rotor bars. The monitoring system efficiently detected an imbalance of
supply, single phasing, and broken rotor bars occurring at different instants of time. The study
overcomes the drawback of FFT techniques which are unable to provide simultaneous time-
frequency information of multiple faults with lesser efforts. To improve the effect of FFT the
scholar uses the STFT method to minimize the time taken to detect fault conditions in the
induction motor again which improves the outage of the system [1][3][6].
P. Diwatelwar and K. Malode studied fault detection and analysis of three-phase induction
motors using the MATLAB/Simulink model. In the thesis study, FFT (Fast Fourier Transform)
approach and the fuzzy logic controller are used to analyze three-phase induction motor input
voltage and current. FFT analysis was used to calibrate THD total harmonics content for normal
conditions and abnormal winding faults conditions. Based on the analysis for both input current
and voltage total harmonics distortion is the minimum for the normal condition which is less
than 2% for three-phase voltage and 80%-95% for three-phase current and for abnormal
conditions total harmonics distortion increases for faulted phases. Both FFT and fuzzy logic
analysis is compared well for fault detection and analysis. The drawback of FFT analysis is
analyzed total harmonics distortion of stator current and voltage only and takes more time to
analyze fault conditions. To improve this problem the scholar proposed another method which
is the fuzzy logic controller method of efficient fault analysis and which works for all
conditions of faults [7].
P. Idowu and et al studied the behavior of fault in the induction motor. Based on studies failure
of IM are due to stator fault, winding break down, and rotor faults. In their study frequency-
based computation of motor operating slip can be estimated by FFT. This method is used to
reduce maintenance costs [8].
According to H. Vishwanath and G. Maruthi carried out the study to detect the air gap
eccentricity faults under varying load conditions by monitoring current and vibration signals.
In this study, the scholar uses a sensor to detect the fault like accelerometer and motor current
signature analysis by using the FFT algorithm. Air gap eccentricity causes the torque ripple,
unbalanced magnetic pull, and lower power factor which results in fault in the induction motor
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like speed pulsating, noise, vibration, bearing wear and tear, and rotor deflection then brings
serious problems in the stator and rotor core. Then, based on the fault detection of this study
motor with a constant air gap gives a symmetrical magnetic field in the air gap having a
fundamental harmonic component and less vibration this again gives no side frequency
generation [9][10].
A. Abhinandan and M. Sidram have proposed a method of induction motor fault diagnosis
using the current signature analysis of FFT and DWT analysis. Current signature analysis in
this study was used to diagnose stator current fault.
In this study sideband frequencies are generated due to fault; conditions are analysed. The fault
detection analysis is compared with normal conditions of machines which reduce machine
outage or increase machine age [11].
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