综合考虑电压等级和运行状态的电网脆弱线路辨识

摘要

为了对电网脆弱性进行一个合理的评估，在考虑电网实时运行状态情况下，引入衡量潮流分布不均衡程度的潮流熵的概念，提出将线路潮流熵变化作为脆弱线路辨识的一个指标。基于复杂网络理论，考虑电网拓扑结构特点，建立节点重要度指标，并结合线路所在电压等级和地理位置，提出脆弱度修正因子。通过综合潮流熵变化、节点电压偏移、节点重要度和修正因子提出城市电网脆弱线路辨识的方法。以某城市电网2011年夏大运行方式为例进行线路脆弱性分析，并进行了时域仿真验证，仿真结果表明该方法能够较好地辨识城市电网中的脆弱线路，与电网实际运行情况相符，特别是能够辨识出承担功率不多但重要的联络线路。通过对 IEEE-39节点系统脆弱线路的辨识也说明了所提方法的合理性和通用性。%For reasonable evaluation on vulnerability of power grid,concept of flow entropy for measuring imbalance distri-bution of flow was introduced and index for identifying vulnerable lines by means of change of flow entropy was proposed in the case of considering real-time running state of the power grid. On the basis of complex network theory and in view of characteristics of topology structure of the power grid,node importance index was established and vulnerability correction factor was proposed by combining voltage grades and geographic position of lines. By synthesizing change of flow entropy, node voltage excursion,node importance and correction factor,method for identifying vulnerable lines of city power grid was proposed. Taking heavy load running mode in summer in 201 1 of some city power grid as an example,analysis on vul-nerability of lines and time-domain simulation verification was carried out. Simulation result indicated that this method was able to well identify vulnerable lines in city power grid especially those important connecting lines undertaking few power which was identical to practical running state of the power grid. Identification on vulnerable lines of IEEE-39 node system stated reasonability and universality of the proposed method.