# Towards Flexible Distribution Systems: Future Adaptive Management Schemes
## 2 Evolution of Flexible Distribution System
### Management Services from Flexible Resources and Communities with Flexibilities  
In the future, DSOs must increasingly enable business opportunities for DERs to provide flexibility services through a marketplace [8; 9]. In Europe, recent regulation, i.e., EU electricity market design [10], as well as related electricity market directive [11], also emphasize the important future role of DSOs and consumers/prosumers with DER for the development of flexible distribution systems. In addition, the target is also to solve local challenges locally [1]. Therefore, increased cooperation between DSOs and TSOs [12] is becoming very important in order to maximize the benefits of flexibilities for the whole power system [13]. Future flexibility markets must enable the highest collaborative value of the flexibilities for all stakeholders [14]. Flexibility services for DSOs and TSOs can be related, for example, to (a) frequency control and balancing, (b) congestion management, (c) voltage control, (d) security of supply/islanded (microgrid) operation, (e) reactive power flow control between voltage levels or (f) network losses minimization. However, different options are also possible for the realization of the flexibility services, e.g., (i) technical, (ii) tariff solutions, (iii) market-based, (iv) connection agreement or (v) rule/grid code-based solutions [8; 15]. Figure 1: Power system readiness level, PSRL evolution that requires simultaneous development and readiness of (i) technology/solutions, (ii) customer, (iii) regulation, and (iv) market and business models. The location of flexibilities in the power system is highly relevant from the value and local (DSO) and system-wide (TSO) flexibility services point of view. For that reason, forecasted and real-time knowledge about the local need and the availability of flexibilities (active \(P\) and reactive \(Q\) power) at each voltage or zone level [16] is one key input for active use of flexibilities in the operation and planning of future DSO and TSO networks. In order to ensure maximum availability of flexibilities for different local and system-level services, new adaptive DER and active network management (ANM) principles are needed in order to avoid local flexibilities use restrictions in distribution networks due to congestions related to thermal or voltage limit violations. Future energy systems will consist of an increased amount of distributed sub-systems with flexible energy resources. These sub-systems can be, for example, energy communities or microgrids. The flexibilities can be used to maximize, for example, household or energy community own benefits and resiliency needs as well as fulfill system operators flexibility and resiliency needs. In this regard, a number of customers could be aggregated and provide various flexibility services for the system operators. For instance, a community of households could help to improve the flexibility of power systems by responding to the network flexibility needs through the use of their controllable appliances. They could also be learned to react according to the different scenarios that can happen for the network, helping to avoid blackouts in emergency situations and improving the power system resiliency simultaneously. From the optimal and efficient operation of future energy systems viewpoint, it would be of importance that these different local energy communities could also complement each other and simultaneously fulfill the societal, customer, and resiliency needs locally at the community level. Different local energy communities could be, for example, (1) campus local energy communities, (2) urban or rural energy community with households, (3) commercial energy communities, (4) hybrid energy communities, (5) industrial energy communities, or (6) mobile energy communities (such as marine microgrids in ships). Ideally, these different flexible energy resources in different energy communities could complement each other on a daily and weekly basis and participate in different and new market schemes.