Towards Flexible Distribution Systems: Future Adaptive Management Schemes

Abstract

During the ongoing evolution of energy systems toward increasingly flexible, resilient, and digitalized distribution systems, many issues need to be developed. In general, a holistic multi-level systemic view is required on the future enabling technologies, control and management methods, operation and planning principles, regulation as well as market and business models. Increasing integration of intermittent renewable generation and electric vehicles, as well as industry electrification during the evolution, requires a huge amount of flexibility services at multiple time scales and from different voltage levels, resources, and sectors. Active use of distribution network-connected flexible energy resources for flexibility services provision through new marketplaces will also be needed. Therefore, increased collaboration between system operators in operation and planning of the future power system will also become essential during the evolution. In addition, use of integrated cyber-secure, resilient, cost-efficient, and advanced communication technologies and solutions will be of key importance. This paper describes a potential three-stage evolution path toward fully flexible, resilient, and digitalized electricity distribution networks. A special focus of this paper is the evolution and development of adaptive control and management methods as well as compatible collaborative market schemes that can enable the improved provision of flexibility services by distribution network-connected flexible energy resources for local (distribution system operator) and system-wide (transmission system operator) needs.

Management of Voltage Flexibility from Inverter-Based Distributed Generation Using Multi-Agent Reinforcement Learning

“…In the context of considerable DER-based generation and a plunge in consumption from the grid, voltage stabilization and loss reduction are provided by remotely controlled inverters standing "behind the meter". Various flexibility services related to active power P and reactive power Q from CIG units can be provided by different modes of primary control of the inverter, through which different types of DERs are connected [12]. More specifically (Figure 2), the primary controller of each DG i, i = 1, .…”

“…In the context of considerable DERbased generation and a plunge in consumption from the grid, voltage stabilization and loss reduction are provided by remotely controlled inverters standing "behind the meter". Various flexibility services related to active power P and reactive power Q from CIG units can be provided by different modes of primary control of the inverter, through which different types of DERs are connected [12]. More specifically (Figure 2), the primary controller of each DG i, i = 1, …, N registers reference voltages, 𝑉 , from the secondary controller and regulates output voltage 𝑉 to the required setting, which is usually achieved using reactive droop control (Q/V strategy) methods without data exchange between CIGs [13,14].…”

Integrated DA Coordination of DER Considering Reliability Constraints for Participation in the Renewable Energy Certificate Market in South Korea: A Case Study in a DER Complex

“…The output eligible for the SMP revenue can be expressed as Equation (9). PCC S t , the output metered at the coupled point, is the sum of the energy injected into the external grid from the renewable, represented by P S2G sp,t , and the BESS, represented by P B2G sb,t , excluding the energy charging the BESS, which is represented by P S2B sb,t .…”

“…Furthermore, DERs in Germany are currently officially capable of providing SRL (Sekundärregelliestung) and TRL (Tertiärregelliestung), as long as the DER passes the prequalification tests with the same technical criteria required for the conventional resources. One of the major types of DER participating in both systems consists of BESS and non-dispatchable renewables, as a BTMG (behind-the-meter-generator) coordinated together [7][8][9].…”

Future Renewable Energy Communities Based Flexible Power Systems

“…However, the solutions were not assessed fully to consider all of the aspects, compared to our paper. The authors or [16][17][18][19] tried to discuss solutions to increase the flexibility of power systems and introduce new sources of flexibility. However, they mainly focus on demand-side resources and do not consider different types of energy for future systems.…”