考虑针对变电站网络攻击风险的脆弱元件筛选方法

Vulnerable Component Screening Method Considering Cyber-attack Risk in Substation

随着通信设备的广泛部署以及信息技术的不断发展,新型电力系统所面临的网络风险不可忽视。考虑攻击者从设备商提供的远程维护配置接口侵入,继而通过智能电子设备(IED)向断路器发送命令导致多条线路跳闸的过程,提出一种考虑网络风险的紧急故障筛选方法。首先,利用广义随机Petri网对变电站受到网络攻击的动态过程进行建模,计算变电站内不同异常状态的稳态概率。然后,给出电力系统所面临IED网络攻击风险的定义,并建立双层混合整数非线性模型来筛选可能被攻击的变电站、IED以及其所控制的线路。最后,基于对偶理论并结合取对数、分段线性化等线性化方法,将该双层模型转化为可由商业求解器Gurobi直接求解的单层混合整数线性优化模型。基于IEEE RTS 24节点和IEEE 118节点系统的算例分析结果验证了该方法的有效性,并证明了经典的N-K以及概率N-K双层混合整数优化模型不适用于IED网络攻击场景下的故障筛选。

With the wide deployment of communication devices and the continuous development of information technologies,the cyber risk faced by the the new power system cannot be ignored.This paper proposes an emergency fault screening method considering cyber risks whose process is an attacker penetrating through a remote maintenance configuration interface provided by an equipment vendor and then sending commands to circuit breakers through intelligent electronic devices(IEDs)to cause multiple line trips.First,the generalized stochastic Petri net is adopted to model the dynamic process of the substation under cyber attack and calculate the steady-state probability of different abnormal states in the substation.Then,a definition of the risk to power systems from IED cyber attacks is given,and a two-layer mixed-integer nonlinear model is built to screen the substations,IEDs,and their controlled lines that are likely to be attacked.Finally,based on the dual theory and the combination of log-taking,piecewise linearization and other linearization methods,the two-layer model is transformed into a single-layer mixed-integer linear optimization model which can be directly solved by the commercial solver Gurobi.The case analysis results based on IEEE RTS 24-bus system and IEEE 118-bus system validate the effectiveness of the proposed method,and prove that the classical N-K and probabilistic N-K two-layer mixed-integer optimization models are not suitable for fault screening in IED cyber-attack scenarios.