接地材料腐蚀速度弱极化曲线评价方法  

Corrosion Rate Evaluation for Grounding Grid Material by Low-polarization Curve Method

作　　者：范璇[1] 王建国[1] 周蜜[1] 韩芳[2] 黄松波[1] 谭昨生[2] 

机构地区：[1]武汉大学电气工程学院,湖北省武汉市430072 [2]沈阳供电公司,辽宁省沈阳市110003

出　　处：《中国电机工程学报》2012年第28期192-198,202,共7页Proceedings of the CSEE

摘　　要：变电站接地材料腐蚀速度选取及接地材料选择是接地网截面校核亟待解决的问题。通过电化学极化曲线实验计算得到材料腐蚀的电流密度可以用于材料耐腐蚀性能的实验室评价,并指导工程选材。采用电化学工作站三电极体系测量了碳钢、镀锌钢及铜3种接地材料在3种不同土壤中的弱极化曲线,对比分析了Barnartt三点法、Jankowski&Juchniwi四点法、单极化方向三点法及线性极化和弱极化结合法等4种弱极化曲线数据处理基本算法的分析效果。由结果可知:4种算法均存在数据利用率低、数据处理过程中可能出现二次根式开方项小于零导致无法得到分析结果和对测量极化曲线拟合效果不佳等缺陷,从而提出将阻尼高斯–牛顿迭代算法引入接地材料土壤腐蚀弱极化曲线数据拟合计算中,解决了弱极化曲线数据处理算法存在的不足,为开展接地材料土壤腐蚀速度实验室评价提供了一种有效的新手段。Corrosion rate ＆ grounding material selection is the key problem of substation grounding grid design. Corrosion current density of grounding materials calculated from electrochemical polarization curve experiment can be used to select material and evaluate the corrosion rate in grounding grid of electrical engineering. Low-polarization curves of carbon steel, galvanized steel and copper in three different saturated soil samples were measured by a three-electrode system ＆ electrochemical workstation first. Then the fitting effects of measured polarization curves using analyzed results of the four basic algorithms, including Barnartt three-point method, Single-polarization three-point method, Jankowski ＆ Juchniwi four-point method and Combination of linear- polarization and tow-polarization method, were analyzed and compared in detail. Results show that, the basic algorithms mentioned above have defects such as data utilization rate is low, or there may be no results to be obtained because the radicand is less than zero during data processing, or fitting effects are poor. Then Levenberg-Marquardt curve-fitting algorithm is introduced to deal with low-polarization curves of grounding grid materials, which is proved to be able to avoid limitations of the basic algorithms. Levenberg-Marquardt curve-fitting algorithm is a new effective measure to evaluate the corrosion rate of grounding grid materials in the laboratory.

关 键 词：接地网 腐蚀速度 弱极化曲线 阻尼高斯–牛顿 曲线拟合 

分 类 号：TM411[电气工程—电器]