DER Capacity Assessment of Active Distribution Systems Using Dynamic Operating Envelopes

Abstract

The increasing deployment of distributed energy resources (DER) within electricity distribution systems can push them outside their safe operational limits. This urges the distribution system operators (DSO) to perform a DER capacity assessment that utilises the network's full potential to accommodate more DER while ensuring the network's safety. However, this is a challenging task as the DER units are mostly consumer-owned and therefore the DSO does not have control over them. To overcome this challenge, this paper first develops dynamic operating envelopes (DOEs). A DOE is a convex set defining acceptable real and reactive powers exchange with the grid at a consumer connection point without violating any network constraints. We propose a novel methodology to calculate a DOE by applying the right-hand side decomposition technique through which we allocate the network's capacity to mutually independent consumers. We then build a hierarchical DER capacity assessment within DOEs that considers the uncertainty of solar power and demand when making investment decisions. In the proposed framework, the consumers are then free to make their decisions as long as they comply with their DOEs.