Electrical Distribution Systems are extensively penetrated with Distributed Energy Resources (DERs) to cater the energy demands with the general perception that it enhances the system's resilience. However, integration of DERs may adversely affect the grid operation and affect the system resilience due to various factors like their intermittent availability, dynamics of weather conditions, non-linearity, complexity, number of malicious threats, and improved reliability requirements of consumers. This paper proposes a methodology to evaluate the planning and operational resilience of power distribution systems under extreme events and determines the withstand capability of the electrical network. The proposed framework is developed by effectively employing the complex network theory. Correlated networks for undesirable configurations are developed from the time series data of active power monitored at nodes of the electrical network. For these correlated networks, computed the network parameters such as clustering coefficient, assortative coefficient, average degree and power law exponent for the anticipation; and percolation threshold for the determination of the network withstand capability under extreme conditions. The proposed methodology is also suitable for identifying the hosting capacity of solar panels in the system while maintaining resilience under different unfavourable conditions and identifying the most critical nodes of the system that could drive the system into non-resilience. This framework is demonstrated on IEEE 123 node test feeder by generating active power time-series data for a variety of electrical conditions using simulation software, GridLAB-D. The percolation threshold resulted as an effective metric for the determination of the planning and operational resilience of the power distribution system.
翻译:配电系统中分布式能源的广泛渗透旨在满足能源需求,通常被认为能增强系统韧性。然而,由于分布式能源的间歇性可用性、天气条件动态变化、非线性特征、系统复杂性、恶意威胁数量增多以及用户对可靠性要求的提高,其集成可能对电网运行产生不利影响,并影响系统韧性。本文提出了一种评估极端事件下配电系统规划与运行韧性的方法,并确定了电网的耐受能力。该框架通过有效运用复杂网络理论构建。基于电网节点监测的有功功率时间序列数据,构建了不良配置的相关网络。针对这些相关网络,计算了聚类系数、同配系数、平均度和幂律指数等网络参数以进行预测;并计算了逾渗阈值以确定极端条件下网络的耐受能力。所提方法同样适用于在维持不同不利条件下系统韧性的同时,确定系统中光伏面板的接纳容量,以及识别可能导致系统丧失韧性的最关键节点。该框架在IEEE 123节点测试馈线系统上进行了验证,通过仿真软件GridLAB-D生成了多种电气条件下的有功功率时间序列数据。结果表明,逾渗阈值可作为评估配电系统规划与运行韧性的有效指标。