Research On Control System Of Reactor Pressure Vessel Head Penetrator Inspection Device

The deterioration or failure of the nuclear reactor pressure vessel head is mainly caused by corrosion cracks in the weld of the head cover penetration.The existence and propagation of cracks will damage the structural integrity of reactor pressure vessel head and threaten human nuclear safety.In order to improve the safety margin of the reactor system and avoid the serious consequences caused by the defects of the head cover,this paper proposes an actuator with probe to complete the defect inspection of the head penetration of the reactor pressure vessel according to the design task.Due to the strong radiation environment and complex space shape of the top cover,the characteristics of the tested object are defined,and the design task of the penetration detection device is determined.The detection principle of scanning action is put forward,and the structure design of penetration detection device is carried out.Aiming at the surface change of the tested object and the axis offset of penetration,the flexibility in the interactive contact between the probe and the tested surface is designed.The driving torque of the motion pair is analyzed to lay the foundation for the control system.Combined with the detection task,the layout of the control system is designed,and the software and hardware schemes of the motion control of the control system are designed respectively.According to the control hardware scheme,hardware selection and emergency stop function design are carried out.The motor motion control based on CANopen bus communication is studied,and the control instruction flow and subroutine function block of motor position and speed mode are established.According to the detection principle,the motor movement subroutine is called to design the inspection program of the top cover side and the pipe wall side,and the communication protection program is designed to improve the system security.In order to improve the interactive contact compliance of the probe following the undulating intersection line of the roof side,the pressure tracking sliding mode control system of the probe is designed.The stability of the system is verified according to Lyapunov theory,and the effect of the designed pressure tracking controller is verified by simulation.According to the hollow structure and power requirements of the rotating pair of the detection device,the double motor current loop master-slave following mode is adopted to drive the load synchronously.According to the characteristics and parameters of the motor and transmission mechanism,the motor model is established and its correctness is verified.According to the actual load,the control models of current loop,speed loop and position loop are established.In order to make the two motors drive the same load smoothly,the PI controller and feedforward gain parameters of the three loop motor are determined by simulation.A dual motor master-slave follow-up test platform is built to test,analyze and optimize the three loop simulation parameters of the motor control system.After optimization,the final position accuracy meets the requirement that the repeated positioning accuracy does not exceed ± 2mm.By comparing the real-time current of single motor and double motor synchronous drive,it is verified that the master-slave motor has good following effect.Build the simulation test platform,test the trajectory process of the probe,verify the reliability of the scanning motion of the detection mechanism.Win CC software is used to establish the configuration interface of upper computer to verify the basic functions of emergency stop,communication protection and incremental position signal output.