Investigation of the Electrical Grid Limitations on Market-Oriented Electric Vehicles using a Multi-Period Optimal Power Flow Model

Electric vehicles can contribute to covering the growing demand for flexibility in the energy system by marketing their flexibility potential. When providing this flexibility in a market-oriented manner, the mobility needs of the vehicle owner, the grid compatibility, the time dependency and the conditions of the market, in this case the day-head market, must be considered. Multi-period optimal power flow models allow market-based optimisation while complying with grid limits and time dependencies. Accordingly, this paper presents the formulation of a multi-period optimal power flow model for controlling electric vehicles. By integrating this optimisation model into a simulation for electric vehicles, the driving and charging behaviour can be precisely modelled in addition to securing the congestion-free grid-operation. Applying this model to a low-voltage grid shows that the optimal bidirectional charging of electric vehicles can lead to profits of €6.3 per day and vehicle. Taking the grid into account and complying with the grid-side limit values leads to a reduction in revenue of around 5% that corresponds to €0.3 per day and vehicle due to the increase in the simultaneity of the charging processes.