高温气冷堆吸收球停堆驱动机构机柜的抗干扰设计研究

Anti-interference design of drive cabinet in absorption sphere shutdown system of HTR-PM

步进电机驱动器是高温气冷堆核电站吸收球停堆驱动机构机柜的主要设备,采用脉冲宽度调制(Pulse Width Modulation,PWM)技术,脉冲宽度调制过程产生的高次谐波分量又反向影响驱动器的工作稳定性和精度,严重时可能引发吸收球误落或拒落而影响反应堆运行安全。本研究旨在制定合理的抗干扰方案,降低PWM脉宽调制机理带来的危害及其影响。在充分掌握PWM产生干扰的传输路径、作用机理和影响程度的基础上,定制适用于高温堆吸收球停堆驱动装置工作环境的光电隔离器、电抗器和滤波器布置在干扰传输路径上阻断干扰传播,降低干扰影响。经过优化设计研究,可使得步进电机每运行20圈,角度偏差在1°之内,满足了控制精度要求,防止了吸收球误落或拒落风险,提升了吸收球停堆驱动机构的运行可靠性。

[Background]Stepper motor driver is the main equipment of the cabinet of Absorption Sphere Shutdown System(ASSS)of High Temperature Gas-Cooled Reactor Pebble-Bed Modules(HTR-PM),which can control the stepper motor to act according to the preset value.If ASSS works abnormally due to the influence of interference,it will cause the stepper motor to run unexpectedly,which may cause the risk of the absorption sphere falling or refusing to fall by mistake and affect normal operation or nuclear safety of HTR-PM.[Purpose]This study aims to formulate a scientific and reasonable anti-interference,so as to effectively reduce the pollution and impact of power grid and grounding system caused by pulse width modulation(PWM)mechanism,and avoid abnormal operation of stepper motor driver.[Methods]Through theoretical calculations and practical tests,the transmission path,mechanism and influence degree of interference caused by PWM were investigated,and customized optoelectronic isolation equipment was designed.Dedicated reactor and filter were installed on the transmission paths of the corresponding interference sources,hence effectively blocking the propagation interference and suppressing its impact,which was in the line with the unique working environment of the cabinet of the absorption sphere shutdown drive mechanism.[Results]The anti-interference design scheme of drive cabinet in absorption sphere shutdown system effectively suppresses the impact of interference on the system,ensures the accurate and stable operation of the stepper motor driver,and realizes the angle deviation of the stepper motor within 1°for every 20 cycles operation,which effectively prevents the risk of malfunction of the stepper motor and improves the reliability of the system operation.[Conclusions]This design scheme has a good guiding significance for the anti-interference design of various control systems of the same type,and has certain promotion significance.