ADMM-based OPF Problem Against Cyber Attacks in Smart Grid.

In the smart grid, the application of information and communication technology (ICT) significantly promotes the efficiency of energy generation and consumption system. However, the integration of intelligence and cyber system to a smart grid can result in serious cyber security concerns and presents the entire power system more vulnerable to be attacked. In this paper, a new cyber attack model with the alternating direction multiplier method (ADMM) based optimal power flow (OPF) problem is introduced and exploited by malicious attackers. To deal with this challenge, a defence mechanism is presented to not only detect the existence of data injection attack, but also mitigate the potential impact to improve the stability of the smart grid. This scheme takes the power measurements between neighbouring nodes into account, and distinguishes the time-delay attack and bad data injection attack by monitoring the measurement variations between received data and predicted data based on the artificial neural network (ANN) algorithm. The simulation results demonstrate that the proposed scheme has the capability of detecting and mitigating the stealthy attacks significantly by using a 33-bus power system. Consequently, it is a significant study in the actual smart grid and can minimise the impact of the cyber attack.