Cyber-Secure Global Energy Equalization in DC Microgrid Clusters Under Data Manipulation Attacks

Abstract

Cyber physical microgrids (MGs) are vulnerable to data manipulation attacks which can lead to significant imbalance in the MG. For instance, data manipulations by cyber adversaries may cause to higher loading of batteries with low state-of-charge. This will lead to degradation of the cycle-life of batteries unless timely intervention is done for malware detection. Therefore, a cyber-secure global energy equalisation of battery energy storage systems in multiple interconnected direct current (DC) MG clusters is proposed in this article for efficient utilisation of batteries. Cyber security is achieved in the framework through the proposed multi-level detection and mitigation paradigm aided by event generators. Firstly, it is the maiden attempt to propose and design a secure global energy equalisation framework for MG clusters. Secondly, the proposed event generators enable segregated defensive actions for leader and follower nodes in the network. This is unlike previously reported works wherein the defense mechanism has been generalised for every node. Further, the results indicate that the proposed event generators help in maintaining continuity of power to critical loads in the system. Extensive time-domain simulations are performed in MATLAB/Simulink under various practical scenarios of ad- versarial intrusions. Controller hardware-in-loop tests employing real-time digital simulator (RTDS) and field programmable gate array (FPGA) based WAVECT Controller are also performed for real-time validation of the proposed technique. Finally, for testing scalability of the algorithm, it is extended to 20 DC-DC converters.