接地网脉冲电磁逆散射多参数成像新方法

The grounding grid plays an important role in the safe and reliable running of substation, The study on detection and fault diagnosis of grounding grid will provide an effective means for its state evaluation. The traditional methods such as electric network analysis and electromagnetic field analysis are difficult to achieve accurate positioning and quantitative evaluation of corrosion and breakpoint, and cannot realize the image reconstruction. This project proposes a multiple parameter imaging method for grounding grid by pulsed electromagnetic inverse scattering. Using the scattering characteristics of electromagnetic wave propagating in different medium surface, the new method establishes the mathematical-physical model combining displacement current and conduction current，analyzes the electromagnetic field propagation characteristics between grounding grid and the surrounding medium. Basing on the inverse scattering this project will give the relationship between the scattering field and the electrical parameters of grounding grid, at the same time, we shall investigate the influence factors on the imaging quality including the excitation parameters, antenna parameters, layout of antenna and so on, so that the image reconstruction of electrical conductivity, permittivity and structure for grounding grid could be realized. Finally, this project will develop high resolution and multiple parameter imaging reconstructing method with independent intellectual property right which is appropriate for the shallow-depth grounding grid.

接地网在变电站安全可靠运行方面起着重要的作用，接地网状态检测和故障诊断研究将为接地网状态评价提供有效手段。传统的电网络分析法和电磁场分析法难以进行腐蚀和断点等故障的定量评估和精确定位，且不能实现图像重建。本项目提出接地网脉冲电磁逆散射多参数成像新方法，利用电磁波在不同介质表面的散射特性，建立位移电流和传导电流共同起作用的接地网电磁场数学物理模型，分析电磁场在接地网及周围介质中的传播特性，结合逆散射问题的研究实现散射场和接地网电参数之间关系的建立，同时考察不同激励参数及天线参数和其布置方式等对成像质量的影响，实现高质量的接地网电导率、介电常数和结构的图像重建。最终开发一种适用于接地网埋深的高分辨率多参数图像重建方法，形成具有自主知识产权的接地网脉冲电磁逆散射多参数成像新方法。

接地网在变电站安全可靠运行方面起着重要的作用，接地网状态检测和故障诊断研究将为接地网状态评价提供有效手段。本项目研究了接地网脉冲电磁逆散射多参数成像新方法，建立了位移电流和传导电流共同起作用的接地网电磁场数学物理模型，分析了电磁场在接地网及周围介质中的传播特性，结合逆散射问题的研究实现电磁场和接地网电参数之间关系的建立，同时考察不同激励参数及天线参数和其布置方式等对成像质量的影响，实现高质量的接地网电参数图像重建。最终开发了一种适用于接地网埋深的高分辨率电参数图像重建方法，进行了接地网模型、塔基接地网及变电站设备接地网现场检测实验，形成具有自主知识产权的接地网脉冲电磁成像新方法。