Abstract:
This work provides a new diagnosis method for broken bar and mixed air gap eccentricity faults in the closed loop control of a squirrel cage induction motor. The closed loop system is widely used in industrial applications due to the efficiency of the variables of the regulator outputs for diagnosis because it directly shows the action of the control. The regulator will continue to force the controlled variables to the reference value, resulting in a decrease in the magnitude of the diagnostic indicators and a loss of information critical for detecting faults that cause a motor disaster. This work Based on the direct stator current fault signature as well as the speed fault signature to return the real magnitude of the fault diagnosis indices without affecting the indirect field control. Furthermore, the real magnitude is used to compensate for the fault magnitude and to obtain a machine operating in a healthy state. Using the discrete Fourier transformation. The transfer function is utilized to find the analytical expression of the measured electrical and mechanical parameters at both conditions. The fault signature and error of the torque are used to compensate for the fault signature speed, torque, and quadrature stator current. The simulation and experiment results are included to verify the effectiveness of the theoretical analysis.
