Alexander Shestakov, Dmitry Galyshev, Victoria Eremeeva, Vladimir Sinitsin, Olga Ibryaeva
Detection of Broken Bar Fault in Induction Motor Using Higher-Order Harmonics Analysis
The induction motors are a part of the bulk critical actuators in metallurgy, engineering and other industries. Generally, industries technological processes limit a redundancy of the critical actuators. Therefore, condition monitoring of the critical actuators parts is the basis of efficiency and reliability of the processes. In turn, the special operate conditions of the actuators, like unsteady speed and load, affects the motor condition monitoring success significantly. Induction motor rotor defects such as squirrel cage damage are minor but leads to unpredicted shutdown and greater maintenance costs. The present study presents a reliable method for detecting defects in squirrel cage rotor bars of the actuator induction motor which runs at various speed and load. The method is based on higher-order space harmonics processing in the motor current signal. The method combines normalization, filtering by variational mode decomposition, wavelet transform and train a convolutional neural network. The method generates a diagnostic model which allows to diagnosis motor rotor bar fault at various speed and load. At the same time, the model requires only one frequency and load for training. The experimental results show the model, which is trained at 35 Hz rotary speed, detects a rotor bar fault at 15 to 50 Hz rotary speed and up to 36% load of the nominal torque with 97% average accuracy. The proposed method is effective for the real equipment operating conditions which have limits of completeness datasets acquisition for training.