Four current developments characterize the ongoing and upcoming changes in the current stage of evolution as indicators of a transitional stage to distributed and multimodal Smart Grids. Thus, they can be understood as transition driving forces:
- First, the generation of electricity is shifted from large capacities in the high voltage grid to small units in the distribution grid. With distributed and renewable energy resources (DER) electricity supply more and more relies on unit types prone to forecast errors. Furthermore, whereas reliability has been most important in the operation of large power plants, small energy units show new dimensions of operational uncertainty .
- Second, whereas in the past flexible loads where mainly allocated in industrial production (and subject to sophisticated contracts and process control), the flexibility potential of small loads in the distribution grid can be added to compensate for missing stabilizing capacity in the high voltage grid, both using direct control and dynamic tariffs .
- Third, more and more autonomous controllers for grid stabilization purposes and the integration of DER are allocated in the electrical energy system. Whereas autonomous controllers have been an important asset in transmission grids for many years , more and more autonomous controllers of different types are now installed in distribution grids .
- Fourth, motivated by the storage demand for largely DER-dominated electrical energy systems, additional flexibility potential will be unlocked by interlinking the infrastructures of different energy systems. Using direct (e.g. conversion of electricity in methanation) and indirect (e.g. shift of energy demand from one energy form to another) coupling of the energy systems, originally unconnected energy systems are dynamically coupled .
The first, second and third transition driving forces enlarge the degree of distribution of the energy system regarding electricity generation, usage and grid operation. The pervasion of the energy system with autonomous controllers leads on to the development of a distributed adaptive system. From an engineering perspective, it shows the desired characteristics regarding scalability and self-stabilization. Unlike these desired aspects, other effects can emerge from the distributed and adaptive nature of this system: Autonomous controllers might counteract, thus leading to unintended system behavior like oscillations and instable system states within a multi-controller system . From the perspective of distributed systems research, these controller conflicts can thus be understood as unintended effects of emergence .
In this project, the evolving multimodal distributed Smart Grid will be modelled as agent-based self-organized system to explore and analyze controller conflicts originating from the emergent properties of the interconnected system. Within a combined approach basing on methodologies from multimodal Smart Grid simulation and recent advances in multi-agent system architectures, metrics will be developed to identify this type of controller conflicts and characterize system states that are prone to controller conflict instabilities.