Grid-Oriented Control of Vehicle Batteries in a Cellular Grid Setup Based on Fuzzy Logic

The electrification of various sectors and the expansion of renewable energy resources (RES) leads to a change from the historically established and planned vertical load flow in the electrical power system to a horizontal one. This is placing a particular strain on the distribution grids to which the new loads and decentralized generators are connected. The cellular energy system approach is expected to work with a high proportion of RES and ensure a high level of supply security. This paper investigates the autonomous control of vehicle batteries for a cellular grid approach. The hierarchically lowest cell manages loads at the household level, in this case, the bidirectional charging of electrical vehicles (EVs). The higher entity ensures safe grid operation at the transformer level. The aim is to optimize the utilization at the transformer and supply line level to avoid congestion. The concept is validated on a test low voltage (LV) grid using three scenarios based on the grid expansion plan in Germany. The results show that a cellular grid approach can help reduce the utilization of operational resources and avoid overload with an unknown action space at the household level. For a future scenario (2037), the overload at the transformer is reduced by 0.72 pu and the overload at the critical supply line is reduced by 0.70 pu.