title: Distribution Grid Restoration using Microgrids: Interdependencies between Power, Water, and Communication Networks
Creators: name: Robison Pietsch, Martin
Publisher: name: UNSPECIFIED
Year: 2025

description: The resilience of urban infrastructure systems—particularly power, water, and communication networks—is crucial for maintaining society's functions during and after crises such as natural disasters or cyber-attacks. 
Traditional approaches to dealing with disasters often treat power, water, and communication networks independently, overlooking dependencies and synergies that could be critical during crises. 
In this dissertation we propose new methods to improve the recovery process in this context. 
All those methods have three strategies in common, which are applied to different problems: 
The dynamic formation of decentral microgrids (MGs), the integration of renewable energy sources and the mutual benefit of the interdependencies of electricity, water and communication networks in the restoration process.

We start by integrating water networks with electrical MGs.
Using the backup generators of the pumps of the water network to initiate local MGs, we can use renewable energy sources in the surrounding neighborhood to reduce fuel consumption during a crisis. 
Optimizing additional valves and switches in each network further allows us to evenly distribute and schedule the limited available resources. 

After ensuring the local restoration of individual MGs, we address how merging them can further enhance overall system stability.
We therefore develop a novel framework to merge individual MGs, considering the explicit need for an active communication link between the MGs generators as a second contribution. 
Here, the communication network depends on a functioning power supply to keep a connection online. 
Merging MGs enhances the operation stability and allows the restoration of larger electrical loads within the network.

In case of damaged communication hardware, we extend our approach to cover gaps in the communication network via unmanned aerial vehicles (UAVs) and optimize their placement considering close renewable battery charging stations. 
Strategic placement of UAVs ensures continuous communication capability, which is vital for coordinated restoration efforts and efficient management of distributed resources.
However, as the optimization of the UAV placement can lead to large combinatorial problems, we increase computation speed by introducing the feasibility query algorithm (FQA), excluding infeasible solutions beforehand.

Finally, we propose a community-power-sharing model, allowing distributed renewable energy resources to support nearby communication infrastructure via MGs using the distribution grid during outages, ensuring critical service continuity.
We demonstrate this approach on two smart buildings at the campus Lichtwiese in Darmstadt and show how power sharing can be implemented in a real-life setup. 

All problems are formulated as mixed-integer linear programs (MILP) and represent different ways to model the interdependencies between power, water, and communication networks. 
This allows for explicit decision-making and scheduling of the restoration process.

Overall, this dissertation aims to enhance urban infrastructure resilience by leveraging MGs and renewable energy resources to integrate and restore interdependent power, water, and communication networks.
By introducing integrated solutions that leverage these interdependencies and exploit renewable energies, the research not only enhances the resilience of individual networks but promotes a holistic and mutually beneficial approach to urban crisis management. 
Our findings offer practical implications for policy making, for shaping economic incentives and the design of resilient urban energy systems and point towards a range of opportunities for future research and further practical implementations.