采用电网直流等效模型评估地磁感应电流水平的影响因素分析

由地磁暴引起的电网地磁感应电流(geomagnetically induced current，GIC)的频率很低，但并不为0，所以采用电网直流等效模型进行GIC水平评估时必然会产生误差。文章分析了线路等效电感、变压器等效电感和高压并联电抗器等效电感对采用电网直流等效模型评估GIC水平所产生误差的影响程度，通过仿真计算分析了变压器绕组联结组别和变压器铁心结构对变压器等效电感的影响，最后针对我国电网的特点，提出了用于评估超、特高压电网电磁感应电流水平的电网等效模型。

Analysis of Impacts on Geomagnetically Induced Current Level Evaluation by Power Network DC Equivalent Model

Although the frequency of geomagnetically induced current (GIC) caused by geomagnetic storm is very low but not equal to zero, the evaluation error is consequential when DC equivalent model of power network is adopted to evaluate GIC level. In this paper the impacting extent of equivalent inductances of transmission lines and transformers as well as that of high voltage shunt reactor on GIC level evaluation by DC equivalent model of power network are analyzed, and by means of simulation the impacts of transformer winding connection modes and structure of transformer cores on equivalent inductance of transformer are researched. Finally, based on the property of power grids in China an equivalent model for the evaluation of GIC level in EHV and UHV power grids is put forward.