Analysis And Processing For Yamadu Hydropower Station Transient Process Abnormal Phenomena

Hydraulic transient is a key for the stability of the hydropower station and closely related with safety and economy. Now it has become a hot topic of hydroelectric power station problem.Base on related research, the big hydraulic torque at guide leads to an obvious difference exist in the closure law of guide vane during load rejection and design (such as guide vane fast closing or pausing), appearing at some station with large water time constant, which bring a serious threat to the safety and stability of the power plant. In this paper, the Yamadu Hydropower Station is taken as an example to simulate the abnormalities of the guide vane during the process of load dumping. The treatment method is put forward and its influence on the transition process is analyzed and compared.Guide vane fast closing and pausing phenomena during load rejection of Yamadu hydropower station are analysed in this paper. A servo system model was builded to quantificationally resolve it. The result shows that guide vanes abnormal closing appearing at first stage of closing period, which is a result of large guide vane hydraulic torque combined with small servomotor force, then add one-way throttle valve and improving servomotor diameter two improvement schemes are carried the verified by computational simulation verification. The guide vanes fast closing and pausing no longer arise during load rejection because of the build of Yamadu hydropower station, add one-way throttle valve method is taken.Finally, the paper analyzes the normal, abnormal and two kinds of improvement schemes, and analyzes the influence and influence of the transition process on the transition process.The conclusion of the paper not only offers a direct theoretical basis to solve Yamadu hydroelectric power station problem, but also provides reference significance for other hydroelectric power station with large water inertia time constant and transient research.