基于正逆问题分析方法的变电站接地网研究综述(英文)

Studies on Substation Ground Grids From the Perspective of Primary and Inverse Problems

接地网对对系统的安全运行起着重要的作用。接地阻抗和变电站地电位升(ground potential rise,GPR)对变电站内设备安全性有直接影响;同时,接触电压、跨步电压、网孔电压和转移电压触摸对站内工作人员安全非常重要。变电站接地网的研究核心问题是如何满足IEEE/GB标准规定的安全阈值。此外,土壤参数、不等间距布置、垂直电极和季节性变化是影响设计和故障定位的主要影响因素。从正逆问题研究的角度来看,正问题主要集中于接地网设计,逆问题则是研究接地网被严重腐蚀后对接地网故障支路的定位。该文对已发表的接地网主要研究成果进行综述,其中,重点介绍了中国学者在变电站接地网故障定位方面的研究进展。根据本课题组在接地网研究中所得成果,提出一个新的研究视角来揭示变电站接地网的正问题和逆问题间的内在联系,可以为接地网逆问题中病态的故障诊断方程提供额外的信息。

Ground grids play an important role in the safe operation of the system. Ground impedance and ground potential rise in substation have the direct influences on the security for equipment while touch voltage, step voltage, mesh voltage and transferred voltage are of great importance for the safety of personnel. In the research of substation ground grids, the core issue is how to make safety parameters meet the threshold specified by IEEE/GB standard. Furthermore, soil parameters, unequal spaced arrangement, vertical electrodes and season are the main influential factors that impact the correctness of design and fault location. In the perspective of solving the primary and inverse problem, the former seems to be the primary problem mainly focusing on the design of ground grids; on the other hand, the inverse problem focuses on fault location after the ground grids have been severely corroded. In this paper, the main achievements of the research on ground grids are globally reviewed; especially, the progress on fault location in China is introduced. Based on the research fundamentals of our group, a novelty research perspective is proposed to reveal the intrinsic connections between the primary and inverse problem of substation ground grids, which can provide additional information for the inverse problem to solve the ill-posed diagnosing equations.