Research on assessment and adaptive correction technology of power system protection fixed value mismatch.

With the increasing integration of distributed energy resources, the issue of protection setting mismatch caused by overlapping fast tripping zones in traditional radial distribution networks has become increasingly prominent, affecting the reliability and selectivity of system protection. This paper focuses on the online evaluation and adaptive correction of protection setting mismatches in power systems, and proposes an adaptive current protection setting optimization method. First, a multi-objective optimization model is constructed with the goals of minimizing fault clearing time, maximizing protection sensitivity, and minimizing the impact on loads, while incorporating key constraints such as coordination between upstream and downstream protection devices. Then, a constrained multi-objective backbone particle swarm optimization algorithm is combined with K-means clustering analysis to solve the model and obtain optimal settings with practical engineering significance. To address the "dead zone" problem, where no optimal setting is obtained under specific topologies, an additional strategy is introduced to optimize the location of sectionalizing circuit breakers along the main line, enabling dynamic correction of protection coverage. Finally, the proposed method is validated through simulations in MATLAB. The results demonstrate that the method can effectively resolve protection setting mismatches, adapt to different distribution network structures, and significantly enhance the overall performance of protection systems in complex distribution network environments.