Structure in Power System Analysis and Control

9610049 Zborszky在以前的工作中，大电力系统的数学结构是在有或没有硬极限存在的情况下作为微分-代数系统来研究的。除了它们的数学结构，物理系统还具有广泛的物理结构，从非结构化到等级或非常严格的结构。大电力系统模型具有非常强的分段(网络结构)结构。动态方程通常分成多个段(由电力系统中的母线物理定义)，仅通过非动态关系(在网络中)连接在一起。在与控制有关的问题中，这种地理结构变得非常重要。在这个项目中，随着数学理论的某些方面的完成，将在控制问题的背景下研究分段系统的分类理论，特别是在电力系统控制的背景下。考虑到电力系统的地理结构，许多控制问题可以分散解决。例如，稳定控制的问题可以表述为跟踪运动目标，该运动目标的每一段都有一个单独的分量，因此可以很容易地在本地计算。分析了这种观测解耦控制的系统稳定性。电力系统的分段结构也导致了建立在观测解耦的单母线群的基本群上的各种群方法。将在分类学理论的基础上对集群式控制方案进行分析。将研究各种控制方法的收敛和精度，并寻找各种情况下最理想的方法--如快、中、慢控制(任务)。快速控制目标大多与保持电力系统的稳定性有关。我们将其表述为跟踪运动目标向量的问题。这个目标很容易分解成相互关联的分段问题，并在跟踪成功时识别稳定的平衡点(请注意，在大多数文献中方便地忽略的扰动的时间尺度上识别平衡是不现实的)。然而，均衡恰恰是在成功跟踪的末尾找到的。这就需要设计有效的近似跟踪方案，从而在这种情况下产生精确的结果。然而，重要的是找到这样的跟踪方案，并准确地确定它们的趋同。这将在项目中完成。针对自动发电控制(ACC)问题的中速控制很容易解决为传统的AGC(单个母线上的设备，称为与联络线相连的单个电力公司的分段，以及由NERC在全国范围内设定期望频率)和新的取消管制的方案(发电站、国家输电公司和配电公司)的三层分段方案。尽管需求不同，但结构相似意味着理论上的联系。将对这些方案进行分析，并寻找最可取的方案。大系统的群集化将是这项工作的基础，这项工作涉及彻底和精确的分析和技术开发。新的分类概念，如状态参数空间内的可观测域和可控域，将在与我们先前的分类工作相对应的彻底性和精确度上进行定义和分析。电力系统正在从地方电力公司发展到基于全国实时商品交易的多层发电、输电和配电公司的AGC控制和监管，这使得这项拟议的研究非常重要，可能非常有用。目前，重组后的系统的最终形态尚未形成，它最终将决定其控制需求的结构。因此，分类方法的灵活性可以适应各种需求和结构，这将使其成为寻找最理想的结构和目标的理想工具。

ECS-9610049 Zaborszky In previous work the mathematical structure of the large power system as differential-algebraic system with or without the presence of hard limits has been studied in the context of an overall taxonomy. Along with their mathematical structure, physical systems have a wide spread of physical structure ranging from unstructured to hierarchical or very strict structures. The large power system model has a very strong segmental (network) structure. The dynamic equations typically separate into segments (which are physically defined by the buses in the power system), tied together only through non-dynamic relations (in the network). This geographic structure becomes of great importance in questions related to control. In this project, along with completing certain aspects of the mathematical theory, the taxonomy theory will be studied for segmental systems in the context of control problems, specially in the control of power systems. In view of the power system's geographic structure many control problems can be addressed decentralized. For instance, the problem of stabilizing control can be formulated as tracking a moving target which has a single component for each segment and thus can be easily computed locally. The systemwide stability of such an observation decoupled control will be analyzed. The segmental structure of the power system also leads to various clustering approaches built on rudimentary clusters of observation decoupled single bus clusters. Clustered control schemes will be analyzed on the basis of the taxonomy theory. The convergence and accuracy of various control approaches will be studied and the most desirable approaches for various circumstances-such as fast, medium and slow control (tasks) will be sought. The fast control objectives are mostly connected to preserving the stability of the power system. We have formulated it as a problem of tracking a moving target vector. This objective readily breaks up into interconnected segmen tal problems and identifies the stable equilibrium point when the tracking is successful (note that it is not practical to identify the equilibrium on the time scale of the disturbances fact conveniently ignored in most of the literature). However, the equilibrium is found precisely at the end of successful tracking. This invites the design of effective approximate tracking schemes which lead in this case to precise results. It is important, however, to find such tracking schemes and establish precisely their convergence. This will be done in the project. The medium fast control for the problems of the automatic generation control (ACC) readily settles into a three layer segmented scheme both for the traditional AGC (equipment at individual buses, segments called Areas for individual power companies connected with tie lines and nationwide setting of desired frequency by NERC) and the new deregulated scheme (generating stations, national transmission company and distribution companies). Although needs are different, the structural similarity implies connections in the theory. These will be analyzed and the most desirable schemes sought. Clustering of the large system will be the basis of this work involving thorough and precise analysis and technique development. New taxonomy concepts such as observability region and controllability region within the state-parameter space will be defined and analyzed at the thoroughness and precision corresponding to our earlier Taxonomy work. The ongoing development of the power system away from local power companies and regulation connected AGC control to layers of generation, transmission and distribution companies based on a real time commodity trading nationally makes this proposed study quite important and potentially very useful. At present the final shape of the reorganized system which will eventually dictate the structure of its control needs is not yet emerging. Hence the flexibility of the taxonomy approach which can accommodate a grea t variety of needs and structure will make it an ideal vehicle for searching for the most desirable structures and objectives.