In recent years, there have been increasing concerns about how geomagnetic disturbances (GMDs) impact electrical power systems. Geomagnetically-induced currents (GICs) can saturate transformers, induce hot spot heating and increase reactive power losses. These effects can potentially cause catastrophic damage to transformers and severely impact the ability of a power system to deliver power. To address this problem, we develop a model of GIC impacts to power systems that includes 1) GIC thermal capacity of transformers as a function of normal Alternating Current (AC) and 2) reactive power losses as a function of GIC. We use this model to derive an optimization problem that protects power systems from GIC impacts through line switching, generator redispatch, and load shedding. We employ state-of-the-art convex relaxations of AC power flow equations to lower bound the objective. We demonstrate the approach on a modified RTS96 system and the UIUC 150-bus system and show that line switching is an effective means to mitigate GIC impacts. We also provide a sensitivity analysis of optimal switching decisions with respect to GMD direction.
翻译:近年来,人们日益关注地磁扰动如何影响电力系统。地磁引发的电流能够饱和变压器,引起热点供暖,增加反应力损失。这些效应可能会对变压器造成灾难性损害,并严重影响电力系统输送电力的能力。为了解决这一问题,我们开发了一个GIC对电力系统影响的模型,其中包括:1) GIC变压器的热能能力是正常交替当前(AC)的功能,2)反应力损失是GIC的功能。我们利用这一模型来产生一个优化问题,通过线交换、发电机再发泄和加载压来保护电源系统不受GIC影响。我们采用了空调电流方程式的状态配置松缩,以降低目标。我们展示了经过修改的RTS96系统和UIUC 150-Bus系统的方法,并表明线转换是减轻GIC影响的有效手段。我们还对与GD方向有关的优化转换决定进行了敏感度分析。