中文摘要：

地磁感应电流（geomagnetically induced current,GIC）侵害变压器衍生的无功损耗具有全网同时性的特点,造成整个电网的无功不足与电压波动,可能威胁电网的安全运行。为此,以电压波动和电容器补偿容量最小为目标,计及发电机组无功出力和变压器可调变比约束,将补偿电容器作为无功优化的控制变量,提出了1种基于改进粒子群算法的多目标无功优化策略。20节点算例的仿真计算结果表明：在地电场强度幅值为1 V/km的地电场作用下,电网电压受地磁扰动的影响较大,大负荷下有5个节点电压越过下限值且最小电压幅值标幺值为0.913;通过多目标无功优化后节点电压得到明显改善,比未优化提高了4%,效果较好。所提出的通过调度手段合理制定的多目标无功优化治理方案,能够减轻磁暴灾害对电网的影响,抑制地磁扰动下电网电压的波动,提高电网抗磁暴风险的能力。

英文摘要：

The reactive power loss of transformer caused by geomagnetically induced current （GIC） has the characteristics of simultaneity during geomagnetic storms, leading to a significant loss of reactive power support and voltage fluctuations in the whole power grid, which may threaten the safe operation of the grid. Therefore, taking the smallest of voltage fluc- tuation and the minimum capacitor compensation capacity as target, considering generators reactive power and transformer adjustable ratio constraints, and regarding the compensation capacitor as the control variable of reactive pow- er optimization, we proposed a multiobjective reactive power optimization strategy based on improved particle swarm algorithms. The simulation results of 20-bus test case demonstrate that the voltage is remarkably influenced by geomag- netic disturbance considering 1 V/km induced electric field, and under the heavy load, five node voltages surpass the lower limit with the minimum per-unit value of 0.913. However, the node voltage has increased by four percent by using multiobjective reactive power optimization strategy. Moreover, we put forward a GIC mitigation proposal which rational- ly formulates multiobjective reactive power optimization strategy by dispatching, and it can significantly mitigate the effect of geomagnetic storms to power grid, suppress the voltage fluctuations caused by geomagnetic disturbances and improve the defense capabilities of the grid from geomagnetic storm disasters.