Congestion Management in LV Grids Using Static and Dynamic EV Smart Charging

In recent years, the adoption of electric vehicle has increased steadily, posing substantial problems in the low voltage grid. Among these problems are grid congestion and voltage instability. This study proposes a dynamic smart charging strategy based on a constant impedance load flow model, in which the optimal electric vehicle charging power is based on the available grid capacity. The dynamic charging profile is compared to a static charging profile and business as usual charging in a case study on a representative low voltage grid. Simulations are made with projections for electric vehicle charging, residential electricity demand and photovoltaic generation for 2018, 2030 and 2050. The results of the case study show that no grid congestion occurs in the 2018 scenario, and little in the 2030 scenario, meaning that the current grid infrastructure is well- suited for the electric vehicle charging demand and that the business as usual and static smart charging profiles result in an underutilization of the grid capacity. Grid congestion occurs substantially more frequently in the 2050 scenario, but the dynamic smart charging profile results in a greater utilization of the grid capacity compared to the alternatives.