Grid and Market Services From the Edge: Using Operating Envelopes to Unlock Network-Aware Bottom-Up Flexibility

Distributed energy resource management systems—DERMS: State of the art and how to move forward

“…), but also an ability to predict possible constraint violations, caused by a dynamic and volatile nature of DERs and EVs. Moreover, as the aggregated, small‐scale DERs, as well as most of the large‐scale DERs (especially energy storages), follow the preset schedules, a look‐ahead module of a Utility DERMS should at least be able to estimate the impact of these scheduled outputs onto the grid assets (Belhomme et al, 2021; Chicco et al, 2020; Liu et al, 2021; Petrou et al, 2021). Thus, like a real‐time module, a look‐ahead module of a Utility DERMS shall contain State Estimation application but based on the forecasted inputs (load and generation profiles, weather forecasts, scheduled operation of DERs and DER groups, etc.…”

“…Further, a look‐ahead module shall at least be equipped with tools to detect critical schedules of DERs and DER groups (the ones that will cause constraint violations in the predicted future periods) and shall be able to propose their modifications to avoid violations. In other words, a Utility DERMS should be able to ingest and re‐calculate the operating envelopes from DERs and DER Aggregators, based on its ability to analyze the influence of their scheduled operation on the network assets (Belhomme et al, 2021; Chicco et al, 2020; Liu et al, 2021; Petrou et al, 2020; Petrou et al, 2021; Riaz & Mancarella, 2021). Operating envelopes are defined by limits in which a scheduled production/consumption of a third party aggregator or a large DER needs to operate, that are calculated based on the predicted conditions in the grid, to ensure that no technical violations are caused by the scheduled operation of these resources.…”

“…However, as their rated powers are generally in a range of several kilowatts, individually they do not possess a leverage to negotiate and offer their services to DSOs, nor it can be expected from DSOs to have communication channels with every single DER connected to the LV level, as discussed in the previous section of this article. However, the aggregated flexibility of large amounts of these DERs may be highly considerable and may present an asset to be used for various tasks, that include balancing voltage and power imbalance at the distribution level, dynamically managing technical constraint violations by using aggregated DER flexibility for NWA and for reliability increase, but also for frequency regulation as well as balancing supply and demand of electric power (ARENA, 2020, 2021a, 2021b; Belhomme et al, 2021; Chicco et al, 2020; Liu et al, 2021; Petrou et al, 2020; Petrou et al, 2021; Riaz & Mancarella, 2021). This is where DER Aggregators come into play, as their main aim is to communicate with and aggregate small, usually behind‐the‐meter DERs into DER groups, and then use their aggregated flexibility and provide various customer‐related and ancillary services to DSOs, or even directly to the TSO (ARENA, 2020, 2021a, 2021b; Birk et al, 2017; Earley, 2020; Gerard et al, 2016; Givisiez et al, 2020; IRENA, 2019; Lund et al, 2019).…”

“…It should be noted that DER Aggregators do not have access to an accurate network model and are unaware of the grid level upstream and its technical constraints, such as transformer and lines' overloads, relay settings and coordination, voltage limits, or reverse power flow constraints (Liu et al, 2021; SEPA, 2021; Strezoski et al, 2022; Strezoski & Stefani, 2021). Thus, even though services provided by DER Aggregators are highly important as they increase the overall flexibility of distribution grids by enabling the usage of the flexibility of small‐scale DERs, in most cases a DER Aggregator cannot be a sole DER management solution, as the schedules and dispatch of DERs provided by DER Aggregators alone may endanger grid assets, if they are not previously validated by the grid‐aware enterprise solution, such as a Utility DERMS (SEPA, 2021; Strezoski & Stefani, 2021).…”

Load Balancing in Low-Voltage Distribution Networks via Optimizing Residential Phase Connections

“…The controllable switches communicate with the controller wirelessly to switch their phase connections after receiving the optimized strategies. Voltages and currents of customers are assumed to be measurable by smart meters and available for the PSD controller via communication with the operation centre [6]. The voltage at the secondary side of DT is also assumed to be available for the PSD controller through fast measurements in the PSD controller [5].…”