Abstract: The unit #5 of Wuxijiang Hydropower Plant is monitoried and controlled by computers and operated at the “unmanned on duty” mode. But there were some problems in its mechanical brake system, including longer time needed for stopping by mechanical brake, mechanical fatigue, deformation and cracking due to friction, and lower automation level. To solving these problems, the electrical brake stopping system has been adopted and relevant test has been carried out for investigating. Now the unit stopping performance is improved, the environment quality and automation level are raised after the brake system reformation.

Key words: hydro turbine generator, electrical brake, mechanical brake