Fatigue life prediction of motor-generator rotor for pumped-storage plant

To predict the fatigue life of motor-generator rotor in a pumped-storage plant, the most dangerous position of the rotor under the highest applied load was found to be at the dovetail of magnetic pole and yoke after failure analysis and stress condition analysis. In this work, two types of steel sheets used to manufacture those parts were chosen to study the microstructures and mechanical properties, especially the fatigue properties. Based on those results, some methods including widely applied Forschungskuratorium Maschinenbau (FKM) method and modified one were used to predict fatigue life of the key parts. Considering possible influencing factors, based on the fatigue theories or methods to modify mean stress and predict fatigue life, a novel method, named key part life (KPL) method, was proposed briefly. The KPL method not only suits well for the motor-generator rotor, but also provides a new idea for life prediction of parts in engineering field.