Advanced Optimal Twin‐Setting Protection Coordination Scheme for Maximizing Microgrid Resilience

The increasing penetration of distribution generators (DGs), such as PV systems, has led to a significant power protection concern for optimal overcurrent coordination. However, existing literature indicates that the traditional phase over current relay (OCR) scheme faces challenges such as instability, insensitivity, and lack of selectivity when handling the integration of DGs and ground fault scenarios. To address this issue, this study proposes a new optimal twin‐setting OCR coordination scheme for phase and ground events using standard and nonstandard tripping characteristics. The water cycle optimization algorithm (WCOA) is utilized to develop a coordinated optimum strategy that mitigates the effects of DGs on the currents and locations of faults across the power grid. To demonstrate the efficacy of the proposed approach, different case studies of an IEEE power network (9 buses) equipped with two 5 MW PV systems are conducted using industrial software (ETAP). Under various fault conditions (phase and ground faults) and power network operation modes (with and without PVs and islanding modes), the outcomes of the newly developed optimal coordination scheme are compared to the results of conventional schemes. The proposed twin OCR coordinating scheme is found to reduce the total tripping time of OCRs up to 62.3% and increase the selectivity of the relays without miscoordination events.