On Oct. 12, the ‘Recommended Procedure for Structural Design of Optical-Storage-Direct-Current Flexible Integrated Building Distribution Network’ standard, led by Zhejiang Ningbo Power Supply Bureau, was approved and published by the Institute of Electrical and Electronics Engineers (IEEE). This is the first international standard independently led and compiled by the company, achieving a breakthrough in the field of building DC distribution international standards.
The optical-storage-direct-current flexible integrated building distribution network is a key end grid connecting distributed photovoltaics, energy storage equipment, and building electrical loads. For a long time, this field has lacked unified technical specifications, voltage standards, and topology design criteria, with prevalent issues such as low investment efficiency, high renovation costs, and insufficient system compatibility, which have restricted the large-scale promotion of new building distribution models.
In January 2025, Ningbo Power Supply Bureau initiated the compilation of the standard. The standard covers building DC distribution networks at 48V to 750V voltage levels, clarifying core technical criteria such as topology structure design and voltage level selection. It applies to new construction and renovation projects of optical-storage-direct-current integrated projects in industrial and commercial buildings. The standard focuses on common industry challenges including optical-storage collaborative operation, flexible interconnection, energy efficiency optimization, and digital management, promoting deep integration of distributed new energy with building distribution networks, and providing universal technical specifications and implementation guidelines for global building DC distribution project construction.
In recent years, relying on engineering practices and technical accumulation in building DC distribution and optical-storage-direct-current-flexible fields, Ningbo Power Supply Bureau has initiated 7 international standards.
Source:State Grid Daily