水产养殖自动化系统的防雷保护技术

Lighting protection technology for on-line water quality monitoring system in aquaculture

雷电引发脉冲电磁场对微电子器件设备造成侵害已成为水产养殖自动化系统损坏的主要原因之一。经对系统的现场实际情况和雷电入侵途径分析,提出了直击雷、雷电感应和雷电波的防护措施。对控制房和DCS柜采用避雷针、独立针的直接雷防护;系统电源分别采用箱式电源避雷器、电源避雷器、模块式电源避雷器作为三级电源保护,减少LEMP雷电电磁脉冲辐射;计算机网络与等电位地网间设置低压避雷器或火花隙,防止信号干扰和避免地电压反击;根据传输速率、工作电平、特性阻抗等,选择通信线路的信号防雷保护器的参数和型号。

The harm to the equipment of microelectronic devices, caused by pulsed electromagnetic fields, which is induced by lighting, has become one of the major reasons for system damage. This article proposes a measure for protecting the on-line water quality monitoring system against the direct lightning strike, lighting induction and lighting wave, and a direct lighting protection method for protecting the control room and DCS cabinet using single lighting rod. For reducing the LEMP lighting electromagnetic pulse radiation, the electrical source uses the box-type power supply arrester, the power supply arrester and the modular power supply arrest- er as the third SPD surge protection device. The low-voltage surge arrester or spark gap is laid between the compute net and equipotential grounding grids for avoiding signal interference and counterattack of ground volt- age. The parameter and model of the signal lighting-protector of lines of communication are chosen according to the transfer rate, work level and characteristic impedance.