Relevance of unbalanced loads in low voltage grids in the context of emerging electromobility

Abstract:
This research paper analyzes the impact of asymmetric loads on the low voltage distribution grids due to the integration of electric vehicle charging infrastructure. Charging stations useused in low voltage distribution gr ids today are designed to connect to the grid with three three-phase, two-phase, or single-phase systems, which leads to varying charging powers powers. The one one- and two-phase charging stations cause additional asymmetry in the power grids grids. Consequently, this might lead to overloading or voltage problems in the electrical elements and hence damage the electrical equipment. To assess the potential impact of the use of asymmetric charging stations, this paper presents an estimation based on three-phase static power flow simulations using the power system analysis tool pandapower. Single-phase charging stations show a higher impact on the power system stability and its secure operation than two- and three-phase charging stations do, though introduce less charging power to the grid grid.