Composite system adequacy assessment incorporating virtual power plants

A systematic procedure for assessing composite system adequacy of power systems incorporating Virtual Power Plants (VPP) is introduced in this paper. The VPP model used in this research work represents an aggregated profile of numerous Distributed Energy Resources together with loads belonging to a specified distribution network. The VPP's performance is evaluated using two new indices — Mean VPP Export (External) and Expected VPP Energy Not Used (External) — defined in this paper. A linearized DC load flow based optimal power flow formulation is introduced as part of the overall proposed composite system adequacy assessment procedure, and the impacts of the VPP's incorporation on reliability at the system and at individual transmission bus levels are quantified. Impacts of variations in parameters like the VPP's point of connection to the transmission grid, forced outage rates of transmission lines, etc., on the VPP's performance metrics are also addressed.