埋地金属管道恒电位参数远程监控系统设计

Design of field monitoring system with constant potential parameters of buried metal pipes

为实现恒电位仪的自动化控制,使金属管道始终处于受保护状态,设计对阴极保护设备恒电位仪的输出保护参数（通电电位、断电电位、交流电位、自腐蚀电位）进行监控的电路。该监控系统以Cortex-M3内核的微控制器STM32为核心,以多通道信号调理电路为数据采集单元,通过RS485总线实现与恒电位仪的通信,采用GPRS作为数据传输网络,将恒电位仪的各项参数采集后发送回服务器,服务器对数据进行分析处理,得出恒电位仪的工作状态以及被监测管道的受保护状态。系统需要调节恒电位仪输出功率时,服务器通过GPRS网络将参数传输到监控系统,监控系统通过RS485总线实现对恒电位仪的控制。实测结果表明：恒电位仪输出电流的测量范围为0~80A,准确度在±0.48%以内;管道通电电位测量范围为-3~3 V,准确度在±7 m V以内,能够实现对埋地金属管道恒电位参数的远程监控。

To realize automatic control of potentiostats and put metal pipes in protection, a circuit has been designed that can monitor and control the protection parameters （on/off potential, AC potential, self-corrosion potential） which are sent out from the potentiostat for cathodic protection equipment. In the monitoring system is composed of a microcontroller STM32 as its core part in kernel Cortex-M3 and a multi-channel signal conditioning circuit as its data acquisition unit. The system is communicated with the potentiostat via bus RS485; the GPRS network is used to collect all the parameters of the potentiostat and send them back to the server; the data is further treated by the server to get the working state of the potentiostat and the protection state of the pipeline monitored. If the output power of the potentiostat needs adjusting, the parameters will be transferred from the server to the monitoring system through the GPRS network and the potentiostat will be controlled by the RS485 bus of the monitoring system. Experimental results have shown that the output current of the potentiostat is measured from 0-80A, with the accuracy inside ±0.48%; the electric potential of the pipeline is measured from -3-3 V, with the accuracy inside ±7 inV. The system can be used to monitor remotely the constant potential parameters of buried metal pipelines.