基于复杂网络理论的分布式发电系统非线性动力学行为及其控制研究

Dstributed generation (DG) is a strong nonlinear and complex dynamic system. With the DG widely applying, generation and transmission of power systems become more economic and efficient. Meanwhile, the structural topology of power system has changed from the traditional simple radialization distribution into complex network distribution, which change the power flow of distribution system. As a result, the uncertainties have been brought into the stability of power system and the requirements of high reliability in power systems become more and more high．On the other hand, recent investigations have indicated that complex network theory is a powerful tool to explore the relation between complex structural topology and performance of system. Thus, it is significant for the secure operation of power systems to study the nonlinear dynamics and control in DG based on complex networks theory. In our project, considering the real structure topology and operation characteristics of the power systems, the model of complex DG networks are constructed at firstly, and then the effects of the characteristic parameter, such as node degree and line betweenness upon the nonlinear dynamics of the complex DG networks and the threshold value of these parameters, in which bifurcation and chaos are triggered in the complex DG networks, are studied using the analytical methods. Furthermore, the degree of property degradation in power transmission induced by bifurcation and chaos of one or some nodes is investigated, and the vulnerability of the structural topology is evaluated. Last, some control strategies are designed and applied to protect the nodes with weak stability, which help to maintain the security operation of power system.

分布式发电(DG)是一种强非线性的复杂动力系统。DG的广泛应用使电网的发电和输电变得更经济，更高效。与此同时,DG 的接入改变了传统电力系统的网络拓扑，使原有的配电系统由简单的辐射型配网变为复杂的网络型配网，从而改变了配电系统的潮流分布，给联合电网的稳定运行带来了不确定性，对其可靠性要求也越来越高。因此研究DG 的非线性动力学行为及其控制对保证电网的安全运行具有重要的理论探索价值和应用参考价值。为此，本课题将首先考虑DG 系统的实际拓扑结构和运行特性，基于复杂网络理论建立DG 系统的网络模型，然后分析节点度和线路介数等特征参数对所建模型非线性动力学行为的影响，解析地导出系统发生失稳行为，如分岔、混沌的参数阈值，在此基础上通过研究网络中某些节点的失稳行为所造成的电网输电性能下降的程度，评估网络结构的脆弱性，确定薄弱节点，进而提出有针对性的控制策略，为保证DG 系统的稳定运行提供理论方法。

分布式发电(DG)是一种强非线性的复杂动力系统。DG的广泛应用使电网的发电和输电变得更经济，更高效。与此同时,DG的接入改变了传统电力系统的网络拓扑，使原有的配电系统由简单的辐射型配网变为复杂的网络型配网，从而改变了配电系统的潮流分布，给联合电网的稳定运行带来了不确定性，对其可靠性要求也越来越高。另一方面，近年来的研究表明，复杂网络理论是研究复杂结构拓扑与系统性能关系的有力工具。因此，基于复杂网络理论研究DG的非线性动力学行为及其控制对保证电网的安全运行具有重要的理论探索价值和应用参考价值。本项目主要完成了如下三个方面的研究工作：第一，考虑了DG系统的实际拓扑结构和运行特性，基于复杂网络理论建立了DG系统的随机型、星型、Newman-Watts小世界型、混合多层型等网络模型，第二，分析了网络耦合强度和拓扑连接概率等特征参数对所建模型非线性动力学行为的影响，解析地导出了系统发生失稳行为，如分岔、混沌的参数阈值，第三，通过研究网络中一个或某些节点的失稳行为所造成的电网输电性能下降的程度，评估了网络结构的脆弱性，确定了薄弱节点，进而提出了有针对性的控制策略，为保证DG系统的稳定运行提供了理论方法。本项目的研究结果对复杂电力系统与电力网络的正常运行具有重要意义。