Analysis of Damage Expansion and Mechanical Strength in End Insulation for High-Power AC Motor with Initial Defects

With the rapid development of modern industry, the demand for stable operation of high-power AC motors is increasing. The insulation performance of the stator end winding of the motor directly affects whether the motor can operate reliably. There is a multi-physical field environment inside the high-power AC motor, and the complex physical environment affects the insulation failure of the stator end winding. In this paper, the finite element analysis of the non-destructive stator end winding insulation layer is carried out by coupling electromagnetic power and mechanical force. The analysis results show that the insulation layer at the slot outlet and the nose end is most vulnerable to damage, and then three-dimensional arbitrary cracks are added to analyze the insulation damage. Finally, the stress strength factor theory is used to analyze the propagation law of insulation cracks. Through the analysis results, it is found that the crack at the notch is easier to expand than the nose crack in the multi-physical field environment. In this paper, the failure behavior of insulation damage of high power AC motor is studied, which provides a reliable theory for the production of AC motor in the early stage and the fault maintenance and prediction in the later stage.