Demand-side flexibility in distributed energy systems has aroused broad attention in recent years. However, existing researches are confined to qualitative descriptions or posterior evaluations on flexibility improvement, but the insightful physical mechanism of how and at what cost the distributed energy system offers flexibility is still unclear, especially when it is involved with multi-energy converters and storage. This paper introduces an exergy-based indicator to quantify the cost associated with flexibility improvement of distributed energy systems, then figures out different mechanisms of flexibility improvement of multi-energy storage and converters contributing to the whole energy system. Finally, a spatio-temporal coordination principle for distributed energy systems is established. Results show that the proposed principle is in good agreement with simulation.
Keywords distributed energy system, multi-energy converters and storage, spatio-temporal coordination principle, flexibility cost, exergy analysis