基于磁感应强度的变电站接地网腐蚀诊断研究

发布时间：2019-01-20 18:35

【摘要】：发变电站接地系统的完好对保障站内运行人员的人身安全和保证电气设备正常运行起着举足轻重的作用。现今随着电网的飞速发展,电压等级不断增高,建造高电压大容量的变电站接地网已成现实,一旦发生接地故障,会产生巨大的故障电流,这就对接地网的性能提出了更高的要求。通过对接地网进行测量获得参数,进而对接地网导体腐蚀情况做出正确的判断并进行相应的维修,这样不仅避免了盲目开挖土壤去寻找腐蚀导体,大大节省了人力和物力,而且可以及时消除隐患,真正做到防患于未然,因此研究接地网的腐蚀诊断方法对维护电力系统安全运行具有重要的意义。论文针对变电站接地网导体腐蚀问题做了详细的分析和研究,基于电磁感应原理,分析了接地网完好和导体腐蚀情况下的地表磁感应强度分布特征,并研究了三种因素即土壤分层结构、激励电流频率、激励电流注入抽出方式对地表磁感应强度分布的影响。在此基础上,通过计算接地网导体上方的地表磁感应强度间的腐蚀距离向量,判断接地网导体的腐蚀位置,根据接地网导体腐蚀时地表磁感应强度的分布规律提出接地网导体腐蚀程度的诊断方法。大量的实例仿真和现场实验验证了论文所提方法的可行性,使接地网在不开挖、不影响变电站正常运行的条件下,对导体腐蚀位置及其腐蚀状态进行诊断。
[Abstract]:The integrity of the grounding system plays an important role in ensuring the personal safety of the operators and ensuring the normal operation of electrical equipment. With the rapid development of power network and the increasing of voltage level, it has become a reality to build a high-voltage and high-capacity substation grounding network. Once the grounding fault occurs, there will be a huge fault current. This puts forward higher requirements for the performance of the docking ground net. The parameters are obtained by measuring the ground net, and then the corrosion condition of the grounding conductor is judged correctly and the corresponding maintenance is carried out. This not only avoids blindly digging the soil to find the corrosive conductor, but also saves the manpower and material resources greatly. And it can eliminate the hidden trouble in time, so it is of great significance to study the corrosion diagnosis method of grounding grid to maintain the safe operation of power system. Based on the principle of electromagnetic induction, the distribution characteristics of ground magnetic induction intensity under the condition of good grounding grid and conductor corrosion are analyzed in this paper. The effects of three factors, namely, soil stratification, excitation current frequency and exciting current injection and pumping mode, on the distribution of magnetic induction intensity were studied. On this basis, by calculating the corrosion distance vector between the surface magnetic induction intensity above the grounding grid conductor, the corrosion position of the grounding grid conductor is determined. According to the distribution law of magnetic induction intensity of earth surface during the corrosion of grounding grid conductor, a diagnosis method of corrosion degree of grounding grid conductor is presented. A large number of examples and field experiments have verified the feasibility of the method proposed in this paper, which makes the grounding grid diagnose the corrosion position and corrosion state of the conductor without excavation and without affecting the normal operation of the substation.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63;TM862

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