考虑保护故障影响的电网关键线路辨识

Identification of Critical Line in Power Grid by Considering the Influence of Protection Fault

电网中某些关键线路对大停电事故的发生有着重要的影响,且保护装置的不正确动作在其中起着推波助澜的作用。为了能够有效预防大停电事故的发生,本文提出一种计及保护装置不正确动作的电网关键线路辨识模型。从网络最大流的角度出发,提出一种节点结构重要度指标,该指标能够全面反映网络连接的结构特征,且克服了复杂网络模型中潮流仅按母线间最短路径流动的缺陷;为了能够有效反映电网实际情形,考虑保护的不正确动作,定义了支路保护脆弱度指标,该指标有效量化了保护故障对关键线路辨识的影响;提出了结合支路结构脆弱度与支路保护脆弱度的综合辨识模型。以IEEE 39节点系统作为测试算例,算例结果验证了本文所提模型的合理性与有效性。

Certain critical lines in the power grid have serious impacts on large-scale blackouts,as well as the protection misoperation.In order to prevent the occurrence of the blackout accident effectively,an identification method of critical line in power grid is proposed by considering protection misoperation in this paper.In view of maximum network flow,an important degree index of node structure is put forward,which can fully reflect the structure characteristics of network connection,and overcome the defects that power flow flows in the shortest paths between buses in complex network model.In order to effectively reflect the actual situation of power grid,by considering protection misoperation,an index of protection vulnerability of branch lines is defined,which can effectively quantify the impact of protection failure on the critical line identification.Therefore,a comprehensive model for identifying critical lines is presented by combining structure vulnerability and protection vulnerability of branch lines.Taking IEEE39-bus system as the testing example,the rationality and validity of the proposed model are verified by the example results.