چكيده به لاتين
Eccentricity and bearing fault in induction motors assign high percentage of electrical motors fault, so the method of detecting this type of fault can be helpful in preventing problems in the industry. In this study, a method is proposed that can detect both types of Eccentricity and bearing fault. Shows its Eccentricity fault at the frequencies in the current signal. To obtain these frequencies, in a laboratory environment, and by generating a fault in the motor, the signals that include the signals of current, vibration and displacement, and using the Fourier and Hilbert-Huang transform, the frequencies intended are obtained. The Fourier transform only the order frequency can be obtained and cannot be obtained information from the time that fault occurs. By empirical mode decomposition (EMD) method, decomposite signal into an intrinsic mode functions (IMFs), and according to these functions and using Hilbert transform the instantaneous frequency of signal was obtained that the frequency variations can be observed in terms of time at each instant. The Hilbert-Huang transform at all times and frequencies has high accuracy and its use in analyzing non-stationary and nonlinear signals is very useful. To obtain the desired results, in addition to using accelerometers and current sensors, we also use the displacement sensor, because the use of only a current sensor can only show us the fault and cannot detect the type of eccentricity fault. In this research, the Eccentricity fault and type of fault can be clearly distinguished.
