Resilience Enhancement of Adaptive Overcurrent Protection for Active Distribution Networks Against Relay-Setting Cyber-Attacks

Cyber-attacks that alter relay settings can cause relay malfunctions, increasing unsupplied energy, and diminishing system reliability. This article addresses the vulnerability of overcurrent adaptive protection schemes in active distribution networks against relay-setting cyber-attacks (RSCAs). The proposed method involves storing settings in the memory of overcurrent relays (OCR) and modifying the active setting group instead of directly updating settings in response to the network conditions changing, such as connection to or disconnection from the upstream grid and the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on/off</small> statuses of distributed generations, thereby preventing OCRs maloperation. Furthermore, the prestored settings are derived using novel coordination constraints to ensure that RSCAs do not lead to miscoordination among the OCRs, thus maintaining network reliability and reducing unsupplied energy. Rather than merely detecting RSCAs, this method leverages the setting group capabilities of contemporary OCRs to develop an adaptive protection scheme based on the IEC 61850 standard for active distribution networks, enhancing resilience to cyber-attacks.