Assessing cross-space risk of cyber-physical distribution system under integrated attack is investigated in this paper. Firstly, a hierarchical structure of cyber-physical distribution network according to IEC 61850 is established and a deliberate attack scenario with limited adversarial knowledge and stealth requirement is developed based on a general linear model for state estimation. Then, we formulate two optimization problems to describe the attack implementation and propagation process and obtain the likelihood of attacks including a robust solution and a risk solution in a fuzzy Bayesian network (BN). On this basis, a physical impact metric is defined as the integrated deviation of system states and measurements. Thus, the cross-space risk assessment can be performed. Finally, the simulation results of case studies demonstrate that the proposed method is effective and provides a broad and clear viewing of cyber-physical distribution system security situation.
A robust defensive strategy for active distribution networks considering multi-uncertainties and island restoration is studied. Firstly, the authors take triple uncertainties into consideration, that is, the attack strategy, the amount of wind power generation and solar irradiation. Next, a trilevel defender-attacker-defender (DAD) two-stage robust mathematical model is established to make full use of the energy storage support capacity and reduce the load shedding. The first stage is to pre-allocate defensive resources, and the second stage is to dispatch emergent defensive resources in the worst scenario to minimize the load shedding. Using column and constraint generation (C&CG) algorithm to solve the model, the original problem is converted into the min main problem and max-min sub-problem. The non-convexity of the sub-problem is relaxed by using the second order cone programming (SOCP) model, and converted to the max problem according to the strong duality theory. Solving the model with returned cuttings iteratively. The simulation results show that the proposed method is effective and the defensive strategy can adapt to multi-uncertainties.
To seek the optimal defense strategy against malicious attacks, this paper proposes a novel defender-attacker-operator model applicable to the cyber-physical power system. The proposed model considers the interdependence in functionality and topology of the cyber network and the power network as well as the cyber network's constraints. The defender aims to minimize the load curtailment caused by the attacker, while the latter intends to maximize the power loss. The operator in the bottom level takes corrective action to minimize the attack consequence. This tri-level model is decomposed into a master problem and a subproblem, based on which the column-and-constraint generation algorithm is implemented to obtain the optimal solution. Comparative case studies based on IEEE RTS-79 system are carried out to demonstrate the advantage of the proposed method, and to investigate the impact of the energy coupling strength, the topologically independent link and the defensive resource. The effectiveness of this model is validated by the sensitivity analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.