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

太阳风暴是由太阳爆炸活动的剧烈爆发引起的，可能导致地磁干扰（GMDs）。在gmd期间，大量带电的太阳高能粒子从太阳光晕中逃逸，到达地球，扰乱地球磁场，并在电力系统中产生不希望的直流电。这将导致电力系统设备过热、过载和异常运行。因此，gmd已经显示出破坏电网正常运行并造成大范围停电的能力。魁北克水电系统的崩溃就是一个突出的例子，超过600万的客户没有电，主要的电力系统设备被损坏；这一事件造成了大约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。该项目的主要目标是准确模拟gmd对大型电力系统正常运行的影响，并制定系统的方法来减轻这些影响，包括电网重构和确定阻塞装置的适当位置。为了实现本研究项目的主要目标，确定了以下两个目标：准确建模和分析GMD对电力系统的影响，以及基于电力系统重构和屏蔽装置安装的GMD影响的系统缓解。为此，本项目对科学界的主要贡献如下：1)电力变压器的光谱元素分析：这将是首次尝试将光谱元素方法应用于电力变压器，并普遍应用于任何电机。由于其紧凑的公式和使用高阶基函数，与传统的有限元方法相比，该技术所需的内存和CPU时间要少得多，因此可以提供更准确的结果，为电机分析提供更好和更高效的平台。本项目受益于该任务的结果，通过更好的变压器饱和建模；GMD对变压器的影响是所有GMD不良影响的根本原因。2)非线性谐波潮流分析：某些非线性现象，如变压器饱和，会引起电力系统谐波。该项目旨在开发一种全面的方法来估计在这些情况下系统电压和电流的谐波含量。尽管在这个问题上付出了巨大的努力，并且过去在该领域取得了进展，但迄今为止还没有针对大规模问题的可靠解决技术。3)基于优化的GMD缓解：为防止GMD造成大面积停电，可采取电力系统重构、安装屏蔽装置等措施。电力系统重构的目的是为电力系统提供更好的稳定裕度，或通过设备计划停机的方式防止不良直流电流在系统中传播。阻断装置安装的目的是通过安装高阻抗的硬件装置来阻断ic在电网中的循环。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方面的更广泛应用。

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.