Coordination of DERs in Microgrids with Cybersecure Resilient Decentralized Secondary Frequency Contro

Abstract

Microgrids are emerging as an important strategy to advance resiliency of modern electric power systems. In this paper, a robust decentralized secondary frequency control design for islanded microgrids is developed to enable resilient coordination and integration of distributed energy resources (DERs). We cast the control problem centrally under steady state and adopt the feedback-based Alternating Direction Method of Multipliers (ADMM) algorithm for solving the decentralized control updates. The ADMM algorithm uses measurements at various points in the system to solve for control signals. Measurements and control commands are sent over communication networks such as Ethernet-based local area networks in the IEC 61850 standard. To enhance the robustness to cyber intrusions, we modify the ADMM algorithm using the Round-Robin technique to detect malicious DERs. As a complementary defense, an agreement algorithm based on a fast computation of Kirchhoff law conditions is implemented for continuously detecting false measurements. The results are demonstrated through simulation for a representative microgrid topology.

Probabilistic Bounds on the Impact of Potential Data Integrity Attacks in Microgrids

“…Assumption 1 is often adopted in the MG literature; see, e.g., [3,10,11,23,24]. This assumption can be justified because of the short power lines in MGs.…”

“…Adjusting the frequency back to the reference set-point requires an additional control layer (i.e., a secondary frequency control design [3,10,24,27]) and is beyond the scope of this work.…”

“…We can calculate the sensitivity matrix Φ by solving (11), and we can subsequently complete the linear approximation in (10).…”

“…However, deployment of MGs requires a hierarchical control framework that includes sensors, actuators, and other intelligent control components communicating over a cyber network, to perform functions such as the distributed voltage and frequency controls in [3][4][5][6]. Consequently, there are growing concerns about the stable and reliable operation of MGs where vulnerability to cyber attacks on communication, measurement, and control systems poses significant threats; see, e.g., [7][8][9][10][11] and references therein. Such attacks are not hypothetical, as evidenced by recent cyber-induced outages in Ukrainian power systems [9].…”

“…Real-time simulators such as RTDS and testbeds have been used to analyze the impact of malicious cyber events and test real-time hardware-in-the-loop systems [12][13][14]. In addition, prior work in [10,15,16] has developed defense frameworks and countermeasures against malicious attacks. Nonetheless, prior efforts have fallen short of continuously monitoring and predicting potential cybersecurity impacts.…”