A risk optimization model for enhanced power grid resilience against physical attacks

Secure operation of the power systems is a major concern of the power system operators, consumers and governments. Besides inevitable malfunction of the power grid components, deliberate disruptions caused by malicious attacks put the security of the power systems at high risk. Transmission systems have been targeted by attackers to interdict the supply of power to consumers. In this paper, we address the problem of the transmission system security and develop an optimization model to determine the optimal investment decision for the resilient design of the transmission systems against physical attacks. We measure the damage of the physical attacks in terms of the load curtailment. We model the optimal protection decision problem as a mixed integer linear programming (MILP) problem to minimize the investment costs such that the risk of the load curtailment exceeding a certain threshold value, after an attack to the power grid, be less than the risk tolerance value, defined by power system operators. We use the small 6-bus test system to describe the problem and our methodology. We run our experiments on the IEEE 24-bus and IEEE 57-bus systems to test the performance of our model. Experimental results show that the developed model is a promising enhancement to ensure secure and safe operation of the transmission systems. (C) 2016 Elsevier B.V. All rights reserved.