用于铝电解电流精确测量的手持式光纤电流传感器研究

Research on the handheld fiber-optic current sensor for aluminum electrolysis current measurement

电流强度是电解铝工艺的基本参数,精确测量电解槽分布电流可提高铝电解生产效率和工作稳定性。本文分析了光纤电流传感器相比于传统电流测量技术在电解槽电流测量中的原理性优势,针对目前光纤电流传感器在现场应用中存在的重复拆装和大电流条件下温度误差问题,创新提出了基于柔性封装的传感光纤插接方案和温度误差与非线性误差二维补偿技术,首次设计研制了手持式光纤电流传感器,测试结果表明:传感器的重复拆装误差小于0.12%,在-40℃~70℃温度范围内测量0.5~30 kA电流时的误差小于0.2%,在某电解槽现场测量立柱母线电流时与控制室显示值的误差小于0.4%,并通过对阴极钢棒分布电流的连续监测和分析,实现了电解槽破损的提前预警。

Current intensity is the basic parameter of the electrolytic aluminum process.The accurate measurement of electrolytic cell current is beneficial to improve the production efficiency and work stability.This article analyzes in principle about the reason why the fiber-optic current sensor has high accuracy in electrolytic aluminum current measurement compared with the traditional current measurement technology.To reduce the repeated disassembly and assembly error and high current temperature error of fiber-optic current sensor in field applications,innovatively proposed key technologies such as the sensing optical fiber plug-in scheme based on flexible packaging,two-dimensional compensation of temperature error and nonlinear error,etc.The handheld fiber-optic current sensor is designed and developed for the first time.The test results show that the error of the sensor under repeated disassembly and assembly is less than 0.12%,the error when measuring 0.5~30 kA current in the temperature range of-40℃~70℃is less than 0.2%.When measuring the column bus current in an electrolytic cell,the error with the displayed value in the control room is less than 0.4%.Through the continuous monitoring and analysis of the distributed current of the cathode soft discharge,the early warning of the damage of the electrolytic cell is realized.