The stability of hydro-generator with large capacity of 700 MW and above with inclined reinforcement stator is one of the key concerns of large capacity inclined reinforcement units. According to the national standard of GB/T 7894—2009 Fundamental Technical Specifications for Hydro Generators

the vibration amplitude of stator frame and core of domestic 700 MW hydro-generator is relatively large in operation. This paper takes the unit of Xiaowan hydropower plant as an example

testes and analyzes the vibration characteristics of the stator system of 700 MW hydropower unit. It uses elastic mechanics and electromagnetic mechanics to establish the mathematical model of stator system

and derives the nonlinear equations of vibration of stator system under electromagnetic unbalanced force. By solving the typical condition

it finds that the low frequency vibration is one of the main reasons for large vibration of the stator system. The conclusion has practical and guiding significance for the operation

maintenance

technical modification and fault diagnosis of hydropower units.