Design Of Steam Generator Water Level Control System Based On Peak Regulation Of Nuclear Power Plant

Energy is the cornerstone of human society and national economic development,and is the basic element of people ’s work and life.Nuclear energy is one of the most important new energy sources in the world.Because of its relatively low carbon and environmental protection,nuclear power generation is the main form applied to human production and life.Due to the abundance of nuclear fuel sources,the transportation and storage are relatively simple,and the nuclear power plant has the advantages of less pollution and low power generation cost,the rapid development of nuclear power is likely to become the future development trend of China.After the completion and commissioning of large-scale nuclear power plants,it is bound to bring some pressure to the power grid,which requires nuclear power units to operate at peak load.At present,China ’s nuclear power units generally do not participate in the load tracking of the power grid.However,when the surge in electricity consumption during the holidays will lead to excessive peaking pressure,nuclear power units will also be required to participate in peaking.One of the fundamental issues in the development and use of nuclear power is the issue of peak safety.The steam generator is the main hub between the first loop and the second loop in the PWR nuclear power plant system.The water level control system of the steam generator plays a vital role in the operation of the nuclear power plant,which directly affects the safety,reliability and stability of the nuclear power plant.In this thesis,the classification and working principle of steam generator are studied and analyzed.If the water level is too high or too low,it will interfere with the normal operation of the steam generator,and even cause the rupture of the heat transfer tube,which in turn causes serious consequences such as radioactive material leakage.The steam generator water level system is a complex system with time-varying non-minimum phase.It has strong nonlinearity and complex structure,which is not convenient for the initial design and research of the controller.Secondly,in order to facilitate the analysis and research,the mathematical model of E.Irving is selected.The feasibility of the mathematical model is verified by simulating the mathematical model on the Matlab / Simulink platform.The working principle of the steam generator and the dynamic characteristics of the water level are analyzed.On this basis,the mathematical model is reduced,and the water level control system for the cascading PID of the steam generator is designed.The Matlab / Simulink platform is used for the simulation to check the performance of the controller.Simulation results show that the controller can fundamentally meet the water level control requirements of the steam generator,and can make the water level reach the preset value and have good anti-interference ability,but its control performance is not excellent enough.In order to improve the efficiency of steam generator water level control,an active disturbance rejection controller is designed.Through simulation and comparison with cascade PID control,simulation results demonstrate that the active disturbance rejection controller has a higher control effect,more robust anti-perturbation capability and faster system response time than the cascaded PID controller.