Research On Adaptive Control Of Control Rod Driving Mechanism

Under the background of energy structure transformation,China’s nuclear power industry continues to develop,the rate of localization continues to improve,and the technological level has been in the forefront of the world.Control rod drive mechanism(CRDM)uses electromagnetic force and component gravity to control control rods,which is an important mechanism to realize power control and ensure safe operation of reactors.At present,researches on CRDM cover many aspects.The use of electromagnetic simulation can study its internal characteristics,which is conducive to the structural optimization and design of CRDM.However,electromagnetic simulation can only represent CRDM in a specific state,and cannot visually display its dynamic process.At the same time,CRDM works in a high temperature environment,and the circuit,magnetic circuit and mechanical motion are coupled with each other during operation,leading to great changes in coil parameters.Therefore,the traditional PI control method is difficult to meet the requirements of coil current control response speed and accuracy.In view of the above problems,this paper mainly completes the following tasks:(1)The structure and action principle of CRDM are analyzed in detail.On this basis,a 2-D axisymmetric electromagnetic simulation model of CRDM is established by using ANSYS Maxwell 2D.By using electromagnetic simulation data,the algorithm combining linear interpolation and mathematical modeling is proposed and the digital model of CRDM is established.(2)The co-simulation model of CRDM drive circuit and digital model was established based on MATLAB,and dynamic change curves of CRDM current,electromagnetic force and displacement were obtained,which provided model basis for the study of CRDM adaptive control method.(3)Based on the discrete mathematical model of the drive circuit,a CRDM adaptive control algorithm combining the forgetting factor recursive least square estimation method and the indirect self-correcting PID control is proposed.(4)The CRDM adaptive control simulation was carried out,and the hardware interface and current detection circuit were designed with the help of the real-time simulator as the controller,and the experimental platform was built to complete the adaptive control experiment.