Abstract: In response to the challenges of high-dimensional nonlinear problems and alternative node strategies that struggle to accurately reflect the actual structural requirements of the distribution network in traditional distributed generation (DG) siting and sizing planning, a DG siting and sizing method based on an improved strategy combined dung beetle optimization algorithm is proposed. Firstly, the weighted active loss objective function incorporating the load sensitivity factor(LSF) of the fusion node is constructed, and the dual-objective optimization model is formed together with the voltage deviation. Secondly, an improved dung beetle optimization algorithm that integrates Piecewise chaotic initialization, random walk perturbation, and cross strategies is designed to enhance global search capabilities and adaptability in complex environments. Finally, through the analysis of the IEEE-33 node distribution system example, a comprehensive evaluation of the optimization scheme is conducted from the perspective of the entire lifecycle, including aspects such as net benefits, investment costs, and carbon reduction benefits. The results indicate that the proposed method not only outperforms various traditional algorithms in reducing network losses and voltage deviations, but also demonstrates significant economic advantages, which validates its comprehensive superiority in both technical performance and economic feasibility.

Key words: distributed power generation, siting and sizing, improved dung beetle optimization algorithm, entire life cycle economic analysis