The Simulation Of Transient Process Of Pressure Diversion Type Hydropower Station

The hydraulic transient process frequently occurs during the operation of the hydropower station.The water hammer and the dynamic changes of the pipe,surge-chamber and water turbine make the hydraulic system in a complicated and unstable state.The transient process is directly related to the safety of hydropower stations and the quality of electric power production.In the face of large amplitude load changes,hydropower stations are entering the transient process of large fluctuation.During the period,the amplitude of the change of the rotational speed of the unit and the amplitude of the change of water hammer pressure under the pipe are the focus of the study,and also the main control parameter to measure the safety of the power station.When the hydropower station is faced with a small amplitude load change,it enters the small wave transient process.This process has a high frequency in the conventional operation of the power station,and the quality of the small wave transient process directly affects the power quality of the power station output.The simulation calculation of the transient process can fully reflect the dynamic changes of the hydraulic parts and mechanical components of the power station during the transient process of large and small hydraulic transient process,which can directly reflect the safety of the power station,and can be used to optimize the control strategy of the power station through the simulation test.On the basis of previous research results,this paper studies the calculation method of transient flow of pressure pipe,and establishes the mathematical model of pressure pipe,impedance voltage regulating chamber and mixed flow turbine unit.By compiling computer program,the models are unified into closed system to realize simulation calculation.Combined with an engineering example of a hydropower station,the security and stability of the large and small hydraulic transient process of the hydropower station are simulated and verified,and the optimal control strategy is put forward for the power station.