Enhancing resilience of advanced power protection systems in smart grids against cyber–physical threats

Abstract

Recently, smart grids introduce significant challenges to power system protection due to the high integration with distributed energy resources (DERs) and communication systems. To effectively manage the impact of DERs on power networks, researchers are actively formulating adaptive protection strategies, requiring robust communication schemes. However, concerns remain over the occurrence of communication connection failures and the potential risks presented by cyber-attacks. This work addresses these challenges by investigating the impact of cyber-attacks on different adaptive overcurrent relays (OCRs) approaches. Here, modern adaptive OCR coordination approaches using different group settings has integrated in evaluating high voltage/medium/low voltage (HV/MV/LV) network model with real network parameters at the MV/LV level. Additionally, a voltage-based relay is developed and employed to enhance protection system performance under various cyber threats, aiming to reduce tripping time and to minimize energy that is not supplied. The results show that voltage-based scheme outperform the traditional adaptive OCRs in terms of response time and mis coordination events under cyber-attacks. In the proposed MV/LV real network scenario characterized by an 89% availability of a 4 MW photovoltaic system, even a brief interruption caused by cyber-attacks can result in significant cost consequences.