Resilient Consensus-Based AC Optimal Power Flow Against Data Integrity Attacks Using PLC

This paper investigates the resilience of consensus-based AC optimal power flow (OPF) for distribution networks against the data integrity attacks (DIA). The distribution network is first decomposed into several autonomous microgrids to achieve consensus-based AC OPF through the alternating direction multiplier method (ADMM). Then the vulnerability of consensus-based AC OPF is analyzed by showing how the dispatch results can be easily altered by attackers through falsifying the information (active power, reactive power, and voltage) shared between neighboring microgrids. Two different attack scenarios, viz., economic-driven attacks and disruptive attacks, are studied to show the malicious influence of cyber attacks on consensus-based AC OPF. A detection and mitigation strategy based on the existing power line communication (PLC) infrastructure is then described, where the critical information is not only shared in the cyber layer, but also through the power lines. Game-theoretic analysis is provided to demonstrate the effectiveness of the proposed mitigation strategy. Furthermore, to validate the authenticity of the information through PLC, a physical encryption method based on the Lorenz system is proposed. The effectiveness of the proposed attack-resilient mechanism is verified using the IEEE 123-bus test system.