Overview of DC Distribution System in Low-Carbon Building—Part II: Key Equipment, Coordinated Control, and Stability Analysis

Building energy consumption contributes to approximately 34% of global carbon emissions. Direct current (DC) distribution technology, characterized by its significant advantages in efficiently integrating distributed energy resources (DERs) and flexible loads, alongside high transmission efficiency, presents promising opportunities for the low-carbon transition of the building sector. This review systematically summarizes the key power electronic equipment, coordinated control strategies, and stability analysis methods within building DC distribution systems. First, it introduces the power electronic converters that interconnect system components, and the DC circuit breakers (DCCBs) responsible for fault isolation and operational mode switching. Second, the paper discusses recent advancements in hierarchical control architectures (including primary, secondary, and tertiary levels), considering the electrical characteristics of buildings, and provides a classification thereof. Concurrently, this review systematically covers small-signal and large-signal stability analysis methods. Comparative analyses highlight the existing gaps in stability criteria for multi-voltage-level systems, particularly when considering line impedance. Finally, focusing on the requirements for building decarbonization and efficient, stable operation, this review provides several future research directions.