Research On The Power Level Control For Nuclear Reactor Based On The Adaptive Control Theory

Pressurized water reactor(PWR)has been most widely used in commercial nuclear power plant.The safe and reliable operation of nuclear power plant has already become the focus of the public.Due to the requirement of load following for nuclear power plant,power-level control system is one of the key techniques that guarantee the safe operation for nuclear reactors.And it is significant meaningful to study on the power level tracking control system.Aiming at the problem of load following for PWR,the power level tracking control method based on adaptive control theory are proposed in this paper.At first the point kinetics model is established.Then Lie derivative is utilized to transform the nonlinear dynamic model into a linear one.Subsequently,the adaptive fuzzy controller is developed by combining fuzzy logic control theory with adaptive control theory and the parameters of fuzzy system can be adjusted online.Likewise,the power tracking error remains in a given bounded region.Considering the uncertainty of reactor system,an adaptive controller based on the state observer is proposed by using Lyapunov stability theory.The adaptive control law which is expressed by nonlinear equation of the state variables can not only compensate for the uncertainty dynamically but also realize the track to the demand power level.Finally the polytopic linear parameter varying(LPV)model is established combining with the LPV theory.Based on this model an adaptive guaranteed cost controller of LPV model with uncertainties is developed,which guarantees the tracking for the demand signal with guaranteed control law while adaptively compensating for the effects of uncertainties.By LMI(linear matrix inequality)techniques of Matlab toolbox and Lyapunov theory,a sufficient gain of state feedback for guaranteed cost control and a parameter adaptation law design are derived for a class of uncertain LPV systems.Considering the influence of uncertainties,the power level tracking control system is simulated on the Matlab/Simulink platform.Simulation results show that the controllers proposed in this paper have good performance in power level tracking while it can restrain the disturbance of uncertainties effectively and guarantee the asymptotic stability of the system.Due to the specific technical requirements of power control system for reactor core,it is essential to verify whether the performance of these three proposed controllers meet therequirements.Under the input of step signal,the performances of the controllers are contrasted and evaluated by the settle time,the maximum overshoot,the maximum rate of reactivity and mean square error.