With the increasing integration of high proportions of renewable energy sources, the carbon intensity in the power flow from the grid fluctuates due to changes in generation structures and loads. Similarly, the carbon intensity within energy storage varies with different charging sources and discharge periods, resulting in complex and variable carbon emission characteristics that require precise modeling. This paper establishes an accurate carbon emission model for energy storage within distribution substations. By considering the impacts of carbon costs and electricity price signals, a strategy for energy storage charge and discharge is proposed with the dual objectives of maximizing economic benefits and minimizing carbon emissions. Finally, the effectiveness of the proposed model is validated through case studies, providing a scientific basis for managing and optimizing carbon emissions in low-voltage distribution networks.