A Novel Protection Scheme for Inverse‐time Overcurrent Protection of High Proportion Distributed Photovoltaic Clusters Based on Improved Grey Wolf Optimizer

ABSTRACT The extensive integration of photovoltaic (PV) power generation has significantly transformed the structure of power grids, leading to increasingly complex fault current characteristics. Inverse‐time overcurrent protection is notable for its ability to adjust operation time based on the magnitude of fault currents, thereby enabling an adaptive response to varying fault severities. Therefore, inverse‐time overcurrent protection is extensively employed in power line protection systems that feature a substantial integration of distributed PV generation. However, the configuration of this protection mechanism often relies heavily on engineering experience, thereby constraining its practical applicability. This paper proposes an optimisation algorithm for inverse‐time overcurrent protection based on the improved grey wolf optimiser (GWO). The simulation example verifies the feasibility and superiority of the proposed model under both two‐phase and three‐phase faults. The results demonstrate that the improved GWO not only enhances the sensitivity and operational speed of the protection mechanism but also ensures selectivity, thereby markedly improving the accuracy and reliability of fault response. The proposed optimisation scheme effectively addresses challenges posed by distributed PV systems, such as bidirectional power flows and dynamic fault characteristics, by reducing the overall operating time while maintaining protection selectivity and sensitivity.