As Germany's energy transition progresses, an increasing number of households are evolving from pure consumers to prosumers, significantly altering their load profiles. Photovoltaic (PV) systems installed on residential rooftops enable homeowners to generate their own electricity. To enhance self-consumption, the German government incentivizes the installation of PV systems with battery storage. However, current battery operation strategies focus solely on maximizing self-consumption-storing surplus energy immediately until capacity is reached. This approach creates problematic grid dynamics: minimal grid interaction during morning hours, followed by significant power injection at midday when storage systems are saturated, and substantial consumption peaks in the evening when electric vehicles are charging. This highly volatile power flow pattern, with periods of minimal, high positive, and high negative loads, poses significant challenges to grid stability.

Methods

While these operational patterns may appear reasonable from an individual household perspective, they become problematic when multiple prosumers behave similarly along a low-voltage feeder, pushing the power grid to its operational limits. Although grid expansion represents one solution, it cannot keep pace with adoption rates. This paper implements fuzzy logic-based energy management in a simulation environment as an alternative approach. The fuzzy controller transforms rigid operational parameters into adaptive control mechanisms that regulate power flow at the grid connection point.

Results

Simulation results demonstrate that the proposed fuzzy logic controller significantly improves grid performance compared to unregulated scenarios. The implementation achieves two critical outcomes: increased energy transfer capacity and prevention of grid congestion. Additionally, the controller successfully maintains voltage levels within acceptable operational bands while preventing overload conditions.

Conclusion

This paper presents the structure and implementation of the fuzzy logic controller and quantifies its effectiveness in relieving grid stress. The proposed energy management system offers a universal solution that can be readily adapted to different low-voltage feeders, potentially reducing the need for conventional grid expansion while supporting higher penetration of distributed energy resources.