Design and Comparative Analysis of Flexible Interconnection Topology Structures for Low-voltage Distribution Networks in Mountainous Urban Areas

Targeting the large-scale integration demands of multiple new energy sources in high-density residential communities in mountainous Guizhou, this paper analyzes the working principles and power characteristics of typical flexible interconnection topologies including back-to-back converters, solid-state transformers, and modular multilevel converters. A multi-dimensional evaluation index system is established covering power loss rate, voltage regulation range, fault isolation capability, engineering feasibility, and economic cost. The analytic hierarchy process (AHP) is applied to calculate index weights and comprehensively score each topology scheme. Results indicate that the three-port back-to-back converter achieves the best comprehensive score, with outstanding balance between multi-source adaptability and engineering feasibility, making it the preferred topology for flexible interconnection equipment in mountainous high-density residential communities.