Modeling And Analysis Of Differential Algebra Model Of Hydro Turbine With Surge Tank

The research of the transient of hydroelectric generating set is significance for power plant safety operation.The basis of the research of the transient of hydroelectric generating set is build the complete model which including the hydraulic system,hydro turbine and generation.Previous studies because of the different focus,the model which is lack of integrity.In view of this,this paper basis of previous studies,building the complete model and discuss the actual problem.The main contents include the following aspects:(1)In the transient model of the hydro turbine,the dynamic of the surge tank usually be regarded as an additional input item or independent variables.In order to eliminate independent variables of the surge tank and reduce the number of unknown variables,in this article,the dynamic of the surge tank is merged into the dynamic of the penstock,and build the differential algebra model of hydro turbine including surge tank dynamics.Compare the hydraulic models which build by traditional ways with the model of hydraulic including surge tank dynamics by simulation.The simulation shows the model is meet transient requirement.(2)Establish the complete hydroelectric generating set control system model,including a classical parallel PID controller of governor,the PI excitation controller,the third order model of generator.Discuss the simulation study of the dynamic characteristics of the hydroelectric generating set the influence of different hydraulic system model to the control quality.Simulation shows that the model of the hydraulic affect the transient process of unit,using the elastic water hammer model can reflect the system details.(3)Select the different control system parameters,based on the model of control system of hydroelectric generating set,discussing the influence of the control system parameters on hydroelectric generating set with the surge tank.The simulation shows that the control system parameters influence the transient process;the control system parameters have no affect in the time of the surge tank water level fluctuation.(4)Analysis the influence factors of the transient process of surge tank of hydropower station having surge tank,including the flow inertia time,area of surge tank,pipe roughness and load disturbance.Simulation shows that the flow inertia time affect transient process,surge tank area and water diversion pipe roughness has influence to the stage of surge tank water level fluctuations,load disturbance degree of transient and surge tank water level fluctuation of dynamic quality have influence.