Fault Tolerance and Security for Power Grid Confguration with FACTS Devices

该合同是在运输工业工程探索性研究（ETI）项目招标下获得的。大型电力系统构成了有史以来最大、最复杂的互联运输网络之一。这些遍布世界各地的电网由大量通过高压交流输电系统以近乎同步的方式运行的能源组成。随着电力系统的发展，占主导地位的大容量电力系统已经形成了由一条或多条传输链路连接在一起的紧密耦合的大型机组。这种情况的发展是区域电力系统之间相互联系增加的结果。随着越来越重的电力传输，这样的系统变得容易发生级联故障，因为动态可以以不可预测的方式耦合在整个系统中，级联故障可能是由自然发生的事件引起的，也可能是由恐怖活动引起的。自然发生的级联故障的例子包括1965年臭名昭著的纽约大停电，以及最近的1996年7月和8月两次加州大停电。由于地理和监管的限制，电网的控制传统上是分散的。电力系统中的节点（称为“总线”）通常在地理位置上彼此相距遥远，它们之间很少或根本没有系统通信，这使得协调控制变得困难。此外，国家电网的不同区域可能由独立的私人或公共实体拥有，其运营场所不同。这也给协调控制带来了困难。最有前途的分散网络控制器之一是基于电力电子的控制器家族，被称为“柔性交流传输系统”（FACTS）设备。这些设备通过快速交换在局部修改系统的拓扑结构。通过选择开关模式，这些器件可以实现各种电力系统的目标，如电压支持、振荡阻尼和稳定性改善。这种能力不仅可以用于提高最大吞吐功率等可靠性目标，还可以用于出于经济原因调整潮流。在电力系统重组的环境下，可以预见的是，电力系统将在整个系统内进行潮流调整，以实现经济目标的最大化。然而，这些设备相对较新，目前很少超过原型阶段，因此它们对传输网络的广泛影响尚未得到彻底分析。虽然这些设备提供了增加的网络功率流可控性，但它们的行为的分散性可能会导致它们之间有害的相互作用。在这个项目中，我们建议利用灵活的拓扑FACTS设备来开发分布式控制策略，以i)检测和减轻有意或无意的级联故障，ii,)制定可以自动适应不断变化的经济和物理环境的操作策略，以及iii)制定交互策略以减轻适得其反的行动。

This award is made under the Exploratory Research on Engineering the Transport Industries (ETI) program solicitation. Bulk power systems form one of the largest and most complex inter-connect transportation networks ever built. These net-works throughout the world consist of large numbers of energy sources operating in near synchronism coupled through a high-voltage AC transmission system. As power systems have evolved, the dominant bulk power system has been formed as large groups of closely coupled machines connected by one or more transmission links. This situation has devel-oped as a consequence of growth in interconnections among regional power systems. With increasingly heavier power transfers, such systems become vulnerable to cascading failure as dynamics can couple throughout the system in unpredictable ways, Cascading failures may be brought on by naturally occurring events, or may be induced through terrorist-type activities. Examples of naturally occurring cascading failures include the infamous New York blackout in 1965 and more recently, the two California blackouts of July and August 1996.Control of the power network has traditionally been decentralized due to geographic and regulatory constraints. The nodes (called "buses") in a power system are often geographically remote from one another with little or no systematic communication between them, making coordinated control difficult. Also, different regions of the national power grid may be owned by independent private or public entities whose operating venues differ. This, too, poses difficulties in coordinated control.One of the most promising decentralized network controllers is the family of power electronics-based controllers, known as "flexible AC transmission system" (FACTS) devices. These devices locally modify the topology of the system by rapid switching. By the choice of switching patterns, these devices can achieve a variety of power system objectives, such as voltage support, oscillation damping, and stability improvement. This ability can be used for not only reliability objectives such as increasing the maximum throughput power, but can also be used to adjust power flow for economic reasons. In the power system restructured environment, it is foreseeable that power flows will be adjusted throughout the system to maximize economic objectives. These devices, however, are relatively new and few are cur-rently beyond the prototype stage, therefore their wide-spread impact on the transmission network has not yet been thoroughly analyzed.While these devices offer increased network power flow controllability, the decentralized nature of their actions may cause deleterious interactions between them. In this project, we propose to utilize flexible topology FACTS devices in developing distributed control strategies to i) detect and mitigate intentional or unintentional cascading failures, ii,) develop operating strategies that can automatically adjust to changing economic and physical environments, and iii) develop interaction policies to mitigate counterproductive actions.