Influence of Stator Ventilation Channel Cutting Length on the Multi-Physics in Air-Cooled Hydro-Generator

In order to study the influence of stator ventilation channel cutting length on its eddy current loss, fluid flow inside ventilation groove and stator temperature, the 1000MW hydro-generator is taken as an example in this paper. Its three-dimension transient electromagnetic field model under double poles and coupled field model of fluid and temperature under one slot pitch are created. The eddy current loss of ventilation channel and the influence of cutting length on that are obtained by the transient electromagnetic field. The distribution of fluid velocity inside stator radial ventilation groove and stator temperature is obtained by the coupled field. The variation of radial fluid velocity and stator temperature is obtained by quantitative analysis when different cutting length is applied in ventilation channel. Results show that the appropriate cutting length of the ventilation channel can be conductive to the fluid flow inside the ventilation groove and lower stator temperature. The conclusion can provide reference for the optimization design of ventilation system of large hydro-generator.