Catastrophic impacts of geomagnetic disturbances on power system operation: Analysis and Mitigation

太阳暴是由太阳爆发性活动的剧烈爆发引起的，它可能导致地磁扰动。在GMD期间，大量带电的太阳高能粒子从太阳的光环中逃逸，到达地球，扰乱地球的磁场，并在电力系统中产生不希望的直流电流。这会导致电力系统设备过热、过载和不正常运行。因此，GMD已经证明了破坏电网正常运行并导致大范围停电的能力。魁北克水电系统的崩溃是一个突出的例子，超过600万用户断电，主要电力系统设备受损;这一事件造成约3亿美元的经济损失。专家估计，严重的GMD有可能造成广泛的长期损失，恢复时间为4至10年，经济损失高达1 -2万亿美元。本项目的主要目标是准确模拟GMD对大容量电力系统正常运行的影响，并开发系统的方法来减轻这些影响，包括电网重构和确定闭锁装置的正确位置。为了实现本研究项目的主要目标，定义了以下两个目标：准确建模和分析GMD对电力系统的影响，并基于电力系统重构和闭锁装置安装系统缓解GMD影响。为此，该项目对科学界的主要贡献如下：1）电力变压器的谱元素分析：这将是首次尝试将谱元素方法应用于电力变压器和任何电机。由于其紧凑的配方和高阶基函数的使用，这种技术需要更少的内存和CPU时间相比，传统的有限元方法，因此提供了更准确的结果和更好，更有效的平台，电机分析。本项目通过更好的Transformer饱和建模从该任务的结果中受益; GMD对变压器的影响是所有GMD不利影响的根本原因。2)非线性谐波潮流分析：某些非线性现象，如Transformer饱和，会引起电力系统谐波。该项目旨在开发一种综合方法，用于估计在这些情况下系统电压和电流的谐波含量。尽管在这个问题上做了大量的努力和过去在该领域的进步，迄今为止，没有强大的解决方案技术存在的大规模问题。3)基于优化的GMD缓解：为了防止GMD引起大范围停电，可以采取诸如电力系统重构和阻断器设备安装等措施。电力系统重构的目的是提供一个改善的稳定裕度，以电力系统或防止不必要的直流电流在系统中的传播，通过设备的计划停电。阻断器装置安装的目的是通过安装高阻抗硬件装置来阻断GIC在电网中流通。该项目将创建基于优化技术的系统方法，以确定最佳缓解策略，同时确保考虑电力系统稳定性和设备负载限制。总之，该项目将创建准确的建模技术和缓解方法，以防止GMD对电网产生严重影响。此外，该项目的成果也将有助于在一般电力系统建模和分析中更广泛的应用。

Solar storms, caused by the violent outburst of explosive activities on the sun, may lead to geomagnetic disturbances (GMDs). During GMDs, a large mass of charged solar energetic particles escapes from the sun's halo, travels to Earth, perturbs Earth's magnetic field, and gives rise to undesirable dc currents in power systems. This results in overheating, overloading, and abnormal operation of power system equipment. As a result, GMDs have demonstrated the ability to disrupt the normal operation of power grids and cause widespread blackouts. The collapse of the Hydro-Quebec system is a prominent example, where more than six million customers were left without power, and major power system equipment was damaged; this episode resulted in economic damages of approximately $300 million. Experts estimate that a severe GMD has the potential to cause widespread, long-term losses with a recovery time of four to ten years and staggering economic losses of $1-2 trillion. The main goal of this project is to accurately model the impacts of GMDs on the normal operation of bulk electric power systems and develop systematic approaches to mitigate these impacts, including power grid reconfiguration and determining proper placement of blocking devices.To achieve the main goal of this research project, the following two objectives are defined: Accurate modeling and analysis of GMD impacts on power systems, and systematic mitigation of GMD impacts based on power system reconfiguration and blocking device installation. To this end, the major contributions of this project to the scientific community are as follows: 1) Spectral element analysis of power transformers: This will be the first attempt in applying spectral element method to power transformers and generally to any electric machine. Due to its compact formulation and use of high order basis functions, this technique requires much less memory and CPU time compared to traditional finite element methods and hence provides more accurate results and a better and more efficient platform for the analysis of electric machines. This project benefits from the results of this task by better transformer saturation modeling; impact of GMDs on transformers is the root cause of all GMD adverse impacts. 2) Nonlinear harmonic power flow analysis: Certain nonlinear phenomena, such as transformer saturation, can give rise to power system harmonics. This project seeks to develop a comprehensive approach for estimating the harmonic content of system voltages and currents under these circumstances. Despite the great deal of effort on this problem and past advancements in the area, to date no robust solution technique exists for large-scale problems. 3) Optimization-based GMD mitigation: To prevent GMDs from causing widespread blackouts, measures such as power system reconfiguration and blocker device installation can be taken. Power system reconfiguration aims to provide an improved stability margin to the power system or prevent the propagation of undesirable DC currents in the system by means of equipment planned outages. Blocker device installation aims to block the GICs from circulating in the grid by installing high-impedance hardware devices. This project will create systematic approaches based on optimization techniques to determine optimal mitigation strategies while ensuring consideration of power system stability and equipment loading limits. In summary, this project will create accurate modeling techniques and mitigation approaches to prevent GMD from having severe impact on the grid. Moreover, the deliverables of this project will also contribute to broader applications in general power system modeling and analysis.