基于内源式EIT的接地网成像基础方法与技术研究

项目名称： 基于内源式EIT的接地网成像基础方法与技术研究

项目编号： No.51477013

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 电工技术

项目作者： 杨帆

作者单位： 重庆大学

项目金额： 95万元

中文摘要： 根据规程，接地网需要定期进行检测确保电力系统运行安全。随着变电站及风电场接地网数目快速增加和土壤污染的日益严重，接地网检测任务与改造成本快速增加。老旧变电站接地网图纸丢失导致支路阻抗检测难度非常大。针对目前接地网支路阻抗检测存在的问题，本项目拟研究基于内源式EIT的接地网支路故障检测方法，首先研究接地网内源式EIT问题的数学模型（包括控制方程与退化边界条件），针对其逆问题的病态性，研究其精细化求解方法，包括高对比度不连续介质、介质尺寸差异大等问题对解的准确性的影响。进而研究基于电阻抗成像原理的接地网支路故障成像技术和接地网的分区成像诊断方法，得出基于EIT的接地网拓扑检测方法和分块测量方法，最后结合交流16通道接地网阻抗测量装置完成对算法的验证与改进。项目的成果可用于接地网腐蚀检测与性能评估，有着重要的理论意义与工程价值。申请人前期研究基础表明：EIT方法可以有效识别电阻率差异大的物体。

中文关键词： 接地网；电阻抗成像；內源式；拓扑结构；支路故障

英文摘要： According to safety regulations, grounding grid need to be periodically tested to ensure the safe operation of the power system. With the grounding grid number increasing rapidly of substations and wind farms, and the aggravated environmental pollution, grounding grid detection task and renovation cost increase rapidly. If ground grid drawings of old substation have lost, it will result in the great difficulties of branch impedance detection. To solve the existent problems of grounding grid branch impedance detection method at present, the project will research the grounding grid branch impedance detection method based on endogenous type EIT. Firstly, the grounding grid mathematical model of endogenous type EIT (including governing equation and degenerate boundary conditions) will be researched. For ill-posed source of grounding grid EIT inverse problem, refinement solving methods are studies, including the high-contrast discontinuous medium and the large differences of medium size influence on the accuracy of the solution. Then the branch fault imaging technology and the partition diagnostic imaging method based on EIT are researched. So grounding grid topology detection method and the partition measurement method are obtained. Finally, the experiment is conducted to verify and improve the feasibility of the method by using the alternating 16-channel grounding grid impedance measuring device. Achievements of the project can be used to study corrosion monitoring and state assessment of grounding grid. So the project has important theoretical significance and construction value.Basis preliminary studies of the applicant show that: EIT method can effectively identify differences between large electrical resistivity objects.

英文关键词： Grounding grid;EIT;Inner-excited;Topology;Branch fault