Dynamics of Microgrids in Distribution Network Flexibility

Distributed renewable energy resources have attracted significant attention in recent years due to the falling cost of renewable energy technology, extensive government incentives, and new applications for improving load‐point reliability. This growing proliferation, however, is changing the traditional consumption load curves by adding considerable levels of variability and further challenging the electricity supply–demand balance. In this chapter, we investigated an application of microgrids in effectively capturing the distribution network's net load variability, caused primarily by the prosumers. Microgrids provide a viable and localized solution to this challenge while removing the need for costly investments by the electric utility in reinforcing the existing electricity infrastructure. A flexibility‐oriented microgrid optimal scheduling model was proposed to coordinate the microgrid net load with the aggregated consumers/prosumers net load in the distribution network with a focus on ramping issues. The proposed coordination is performed to capture both inter‐hour and intra‐hour net load variabilities. The proposed model optimally schedules microgrid resources for supporting the distribution grid's flexibility requirements. These flexibility requirements were considered in terms of net load ramping limits. The model was studied for intra‐hour and inter‐hour time intervals during the 24‐hour day‐ahead operation. The Θ‐k islanding criterion was further taken into account to ensure that the microgrid has the capability to switch to the islanded mode, if needed, while supporting the utility grid during the grid‐connected operation. A set of case studies was conducted on a test distribution feeder with one microgrid and several consumers and prosumers to demonstrate the effectiveness of the proposed model. The results showed that the grid operator can efficiently leverage the flexibility of existing microgrids in distribution networks to address some of the most pressing flexibility‐associated challenges while eliminating the need for costly investments in the generation and distribution facilities.