Model, calculation, and application of available supply capability for distribution systems.

• The mathematical model of ASC and its calculation method are proposed. • The model of optimized ASC (OASC) is proposed, which can further exploit the ASC. • The ASC obtained is complete and precise as it considers all load growth patterns. • The ASC obtained can be used for real-time evaluation of supply capability margin. This paper proposes the mathematical model, and calculation method of available supply capability (ASC) for distribution systems. Firstly, the mathematical model for ASC is established, considering all allowed load increments from the present operating point to the security boundary of a distribution system. Secondly, the calculation method for the ASC model is proposed. The results of the proposed method can describe the available supply capability of a distribution system completely, including not only the ASC values, but also some other important data, such as all load growth patterns and cross-boundary points when the system reaches its security boundary. Finally, an IEEE RBTS test system with DGs is used to demonstrate the proposed models and method. Similar to the ATC of the transmission systems, the proposed ASC is an important operational index that can help operators accurately evaluate the supply capability margin of a distribution system. The ASC relevant operational guides are also given in this paper. This work lays the foundation for establishing the ASC theory for distribution systems, which corresponds to the ATC theory for transmission systems. [ABSTRACT FROM AUTHOR]