特高压直流接地极选址及受端电网结构偏磁电流抑制策略研究

Tactical Study on Site Selection of Grounding Electrodes and Suppression of Receiving-end Grid Structural Bias Current in UHV DC Transmission

常规的特高压直流接地极选址及受端电网结构偏磁电流抑制方法主要使用CDEGS软件确定电流抑制修正关系,易受接地极电位差变化影响,导致不同测点的偏磁电流过高,因此需设计一种特高压直流接地极选址及受端电网结构偏磁电流抑制策略。根据地质构造及断裂关系生成特高压直流接地极选址流程,设计受端电网结构偏磁电流抑制算法,从而完成特高压直流接地极选址及受端电网结构偏磁电流抑制。实验结果显示设计的直流接地极选址及电网结构偏磁电流抑制策略的各个测点的偏磁电流较小,表明该策略抑制效果较好、可靠性高,有一定的应用价值。

The conventional methods for site selection of grounding electrodes and suppression of receiving-end grid structural bias current mostly use CDEGS software to determine current suppression correction relationship,which is susceptible to changes in potential differences of grounding electrodes,resulting in high bias currents at different measurement points.Therefore an effective tactic of site selection and bias current suppression is of necessity and studied in this paper.Based on geological structures and fracture relationships,a process flow for grounding electrodes site selection has been generated,and an algorithm for bias current suppression has been designed.The proposed scheme has been proved by experiment capable of achieving small bias current values at all independent test points,and thus superior in suppression utility and reliability.