Impact of the EHV Power System on Geomagnetically Induced Currents in the UHV Power System

Abstract

Earlier calculations of geomagnetically induced currents (GIC) in Chinese power grids have been mainly concentrated on the highest voltage-level system whose geomagnetic risk is considered to be the largest, thus ignoring secondary voltage-level systems. With the 1 000 kV system being newly added to China's power system, it is significant to figure out the interaction between GIC in the 500 kV (EHV) system and GIC in the 1000 kV (UHV) system. Based on the North China-Central China-East China Power Grids, this paper establishes a single-voltage grid by only considering the 1 000 kV system and a dual-voltage grid by considering the 1 000 kV and 500 kV systems and investigates GIC in these two grids by developing their GIC "Full-node models". The impact of the 500 kV system on GIC in the 1000 kV system is analyzed. GIC risks in the UHV and EHV systems are assessed by comparing calculated GIC data with monitored values of GIC. The results show that the impact of the 500 kV system on GIC in the 1000 kV system is obvious, both the EHV and the UHV grid have a high GIC risk. So calculating GIC in the UHV system and in the EHV system should utilize GIC modeling methods for multi-voltage power grids.

Modeling geomagnetically induced currents

“…Guo et al . [] investigate the effect of the extrahigh‐voltage (500 kV) grid on GIC in the ultrahigh‐voltage (1000 kV) system in China and show that the effect is significant.…”

“…Later, it was recognized that GIC could affect power systems all over the world and GIC studies were made in many countries. Specific studies that included modeling of GIC have been done for the UK [ Erinmez et al ., ; McKay , ; Turnbull , , ; Kelly et al ., ]; the U.S. [ Radasky et al ., ; Arajärvi and Viljanen , ; Gilbert et al ., ; Bernabeu , ]; South Africa [ Koen , ; Bernhardi et al ., ; Ngwira et al ., ; Taylor et al ., ]; Sweden [ Wik et al ., ]; Norway [ Myllys et al ., ]; Spain [ Torta et al ., ]; northern, central, and southern Europe [ Viljanen et al ., , ]; France [ Kelly et al ., ]; Australia [ Marshall et al ., ]; New Zealand [ Marshall et al ., ]; Brazil [ Barbosa et al ., ]; Uruguay [ Caraballo et al ., ]; and China [ Zheng et al ., ; Liu et al ., , ; Guo et al ., ].…”

Observation studies of encroachment by geomagnetic storms on high-speed railways and oil-and-gas pipelines in China

“…由于高铁电气设备沿铁路的沿线分布, 牵引变 压器、 自耦变压器和扼流变压器等设备之间的距离比 较远, 以及高铁电气系统的 GIC 流通路径复杂, 如何 用一台监测装置采集到更多的信息, 尤其是流过图 1 [10] , 电网 GIC 的特征规 律清楚, 而高铁电气系统遭受 GMD 侵害的情况更复 杂, 包括系统中 GIC 的流通路径、响应机制, 影响低 压信号系统, 受列车运行影响和电气设备的构成等 都与公共电网不同. 对油气管道, 目前已认知的影响 是 GIC 会加速管道的腐蚀、 降低使用寿命, 在科学问 题上, 虽然金属管道也是导电体, 但由于埋地管道的 内外壁涂有绝缘涂层, 受 GMD 侵害的感应电场机理 及其效应(包括 GIC 和 PSP)与电网不同 [21] , 以及油气 管道有管道长短、 口径大小和管壁薄厚等结构和构成 上的差异等.…”

“…2000 年, 针对我国的 西电东送、全国联网发展战略, 华北电力大学提出并 研究我国规划建设的大规模西电东送电网会不会存 在 GIC, 会不会对未来电网的安全构成严重的威胁. 随着研究的深入, 获得了地磁暴侵害广东和江苏等 电网 GIC 的观测数据 [7] , 发现了我国存在南北向地电 场比东西向地电场更大的现象 [8,9] , 以及导线电阻小 是未来电网 GIC 大的原因 [10] , 揭示了双电压等级电 网 GIC 的相互作用与影响的特征与规律 [11] . 这些研 究成果, 完善了地磁暴侵害电网的科学理论, 证明了 我国未来大电网存在地磁暴灾害的风险, 灾害防御 已得到国家相关部门重视.…”

Comparative Study of Single-phase Shell & Core Type Transformers in GIC Temperature Rise Effect

“…During the severe geomagnetic storms on November 9 to 10, 2004, the maximum GIC at the Ling'ao Nuclear Power Plant reaches up to 75.5A [4]. The1000kV UHV (ultra high voltage) power grid in China, which has been under construction since 2009, adopts 500 mm 2 eight-bundled conductors for the transmissions lines which has smaller DC resistance than that of 500kV power grid, plus the terminal substation effect of GIC, the GIC in the1000kV Shanghai Substation is estimated to be 346.62A at maximum [5]; and the GIC in transformers in Ximeng Substation which is included in the planning Sanhua UHV Grid could reach 442.9A [6]. These data show that the DC bias prevention and mitigation of the effects have become an important task in the construction and operation of China's power grid with the development of UHVDC and continuous reduction of DC resistance of the transmission lines.…”