PID design and simulation of TMSR nuclear power control system

Background: Power Control System(PCS) is one of the most significant systems in Reactor Control System(RCS).PCS accomplishes functions such as power lifting,power maintain and power regulation.Purpose: In the solid reactor design scheme in Thorium-based Molten-Salt Reactor(TMSR) nuclear energy system,power controller is designed to generate signals for control rod moving direction and distance according to the deviation and deviation change trend between the measurement power value and preset value with classical Proportional Integral Derivative(PID) control algorithm.Methods: The PID design of PCS has a relationship with the characteristics of closed control loop which is constructed by reactor neutron physics,thermodynamics and transmission performance of control rods.Different design parameters determine various control system steady and dynamic performance.It is important and necessary to give a parameter set that can provide required characteristics for the control models.With the perspective of control engineering,this paper gives simulation and parameter analysis of PID algorithm of PCS on the basis of control rod control system and positioning system that has already been constructed and fundamentals of neutron physics.Apart from this,the controllable and measurable characteristics of two control models(a traditional control model and an improved multiple-loop control model) are investigated.Results: The system controllable and measurable characteristics analysis from transfer function of two control model showed that our control objects were completely controlled and completely measured in any state.The PID design and the simulation results demonstrated that the two control model both achieved satisfactory tracking performance and robustness with appropriate control parameters.Conclusion: In fact,compared with the traditional model,the improved control model which is of practical significance has better dynamic characteristics,especially in working against unmeasurable disturbances.