冲击大电流下考虑土壤参数频变与时变的大型接地装置特性与模型研究

项目名称： 冲击大电流下考虑土壤参数频变与时变的大型接地装置特性与模型研究

项目编号： No.51277107

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 电工技术

项目作者： 张波

作者单位： 清华大学

项目金额： 84万元

中文摘要： 接地装置的冲击特性对杆塔防雷效果有很大影响。由于土壤电离、频变等非线性现象，已有的接地装置工频特性和基于小尺度模拟试验的冲击特性研究成果无法可靠用于评估大型接地装置的冲击特性，近年来研究大电流下大型接地装置的冲击特性及其仿真模型成为国际研究的热点。课题针对冲击大电流下考虑土壤参数频变与时变的大型接地装置特性与建模问题，研究土壤电阻率和介电常数的频变特性、冲击大电流下土壤电离的时变特性，建立考虑土壤时变和频变特性的理论模型和经验公式；通过大型接地装置大电流冲击实验及沿导体的电流分布测量，考虑接地体电感和电位屏蔽作用，研究大型接地装置沿导体的土壤电离分布规律，获得接地装置冲击特性；综合以上研究成果，提出同时考虑时变和频变非线性特性的大型接地装置大冲击电流下的仿真模型和计算方法。不但在基础理论研究方面取得突破，还将为实际接地装置的优化设计以及防雷分析提供有力支持。

中文关键词： 土壤放电；接地装置；冲击暂态特性；输电线路；雷电防护

英文摘要： The impulse characteristic of the grounding system plays an important role on the lightening protection. Considering the nonlinear phenomena of the soil such as ionization and frequency-varying, the characteristic based on the power frequency analysis or simulation test cannot be applied in the estimation of the large grounding system under strong impulse. So in recent years, the researches on the large grounding system under strong impulse taking the time-varying and frequency-varying characteristic of the soil into account, become a hotspot of the international studies. This project pays attention to the frequency-varying characteristic of the soil resistivity and permittivity and the time-varying characteristic resulted from ionization. Based on the results, the project attempts to summarize the theoretic model and empirical formula. Moreover, based on the real test on large grounding system with strong impulse, the project researches on the impulse characteristic of the grounding system including the relationship of the voltage and the current, the current distribution and soil ionization along the grounding conductor. Based on the testing results, the project also tries to put up a simulation model and a calculation approach which consider the frequency-varying and time-varying characteristic of soil as wel

英文关键词： Soil discharge；Grounding system；Impulse transient characteristic；Transmission line；Lighnting protection