| Feedwater pump is a power plant which is used in the feedwater system of boiler and unclear reactor system,and it is generally the kind of centrifugal pump,the operation of feedwater pump is directly relative to the balance of the water of the whole system,so the research of the dynamic behavior of feedwater pump when the load of unit is changed is very necessary. In order to get the reasonable control strategies and to keep the pump run reliably , neatly and rapidly, it is also necessary to get the transient behavior of the feedwater pump.In a lot of issues, the model of feedwater pump is given with its characteristic curve,this model can reflect the static relation of the main parameters of the feedwater pump,this is necessary to the selection and design of the pump.but this static model can not reflect the dynamic behavior of the feedwater pump when it runs from one steady state to another.Two methods of getting the dynamic model of centrifugal pump are introduced in this thesis,namely the models based on the external characteristics and interior characteristics, the computer simulation and the dynamic model of feedwater pump in a certain feedwater system are also given here,the result shows that both of these methods can get good result when they are used in the single centrifugal pump system,but when used in the parallel connection pump system, the later is more useful than the former.In this feedwater syetem,the control of the feedwater is achieved by regulating both the pump and the feedwater regulating valve,the aim of regulating the pump's rotation speed is to keep the pressure drop of the feedwater regulating valve invariable.two methods to regulate the rotation speed of the pump are given in this thesis,namely the AC voltage-speed regulation and DC voltage-speed regulation, the PID controller and NN-PID cotroller are also stated in this thesis,the computer simulation results show that the NN-PID controller is better than the PID controller.
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