地磁暴是全球范围内地球磁场的剧烈扰动现象，在电网中产生地磁感应电流(GIC)。电力变压器在GIC的作用下进入半波饱和状态，其产生的谐波和增加的无功损耗影响电网电压稳定，造成系统中继电保护装置误动，随着电网电压等级的提高和电网规模的扩大，地磁暴可能严重威胁电网安全运行。分析了变压器对GIC入侵后的响应，以及次生灾害在电力系统中的传播过程，阐明了磁暴对电力系统的影响机理，分析了GIC对变压器、无功补偿设备和继电保护装置等设备的影响，建立了GIC对系统电压稳定性影响的分析框架及基本方法，最后提出了一种GIC优化治理策略，与传统治理方法相比具有明显的优越性。

Geomagnetic storms are violent disturbances of the geomagnetic field around the world, which produce geomagnetic induced currents(GIC) in power system. Power transformer enters the half-wave saturation state under the influence of GIC. The harmonics and reactive power loss produced by transformer affect the voltage stability of power system and cause the maloperation of relay protection devices in power system. With the increase of voltage level and the expansion of power grid scale, geomagnetic storms will seriously threaten the safe operation of power grid. Based on the analysis of the mechanism of magnetic storm disaster and the description of fault propagation and power system response, this paper deeply understands the influence of geomagnetic storm on power system and its electrical equipment. The prevention and control of secondary hazards of GIC is an important subject in the study of geomagnetic storms. This paper summarizes the research framework and ideas of the impact of magnetic storms on the voltage safety of power grid, combs the research results of the optimal control devices for suppressing DC bias of transformers. An optimized treatment of GIC is proposed which has obvious advantages compared with traditional methods.