分布式电源接入对系统脆弱性影响分析

Impact of Distributed Generation on Power System Vulnerability

微电网脆弱性评估即是找出电网自身的薄弱环节,以增强其安全稳定性,但传统的脆弱性评估忽略了电网本身结构特性以及分布式电源的接入对微电网脆弱性的影响;基于此,对分布式电源(Distributed Generation,DG)加入系统前后节点的脆弱性进行了比较分析;有针对性的提出加权的综合脆弱性指标,其中结构脆弱性指标是基于节点度数和线路电抗值对节点重要度进行评估;运行脆弱性指标包括各节点的电压质量和线路的有功功率平衡度;对加入不同类型DG的IEEE33节点系统进行仿真计算,得出不同类型DG以及不同并网点的系统脆弱度,充分评估分布式电源加入对系统脆弱性的影响;仿真算例验证了所提指标的有效性,且不同类型分布式电源的接入能够有效降低系统脆弱性,提高系统的安全性能。

Vulnerability assessment is a method that find out weak link of microgrid to enhance its security stability,which neglect influences of Structural characteristics of power grid and distributed generation connected.Based on this situation,the node vulnerability of system with and without the distributed generation（DG）is compared and analyzed.A weighted integrated vulnerability indicator is proposed to assess the vulnerability of microgrid.Structure vulnerability put forward a method to evaluate node importance based on node degree and line reactance.Run vulnerability indicator includes voltage quality of each node and the active power balance of line.The proposed method has been tested in IEEE 33 bus systems with different types of DG,The effect of power system with distributed generation on system vulnerability is evaluated by comparing the effects of different types of DG and different parallel points.At last,simulation results verify the validity of the proposed indicators,and different types of DG can effectively reduce system vulnerability and improves the system＇s security.