Charging strategies to minimize the peak load for an electric vehicle fleet

Charging of a large number of electric vehicles (EV) at the same time raises several technical problems or can have significant impacts on power systems like high peak power consumption. During daytime, when EVs are connected at the different charging stations at the same time, they can cause a congestion problem in the network. The paper proposes charging strategies to reduce the peak load. These strategies are based on the interruption (on/off) or the modulation of EV charging power. By dividing the daytime in many intervals, a binary linear programming combined with the bisection scheme is used to manage the charging plan of the vehicles. The first application is used for reducing peak load in daytime. The second application is proposed to limit the charging power during a time defined by DSO (or TSO). The performance of the proposed strategies is validated by simulations for a charging station of 50 electric vehicles with a fast calculation time. The results obtained show that peak power can be reduced by more than 50 per cent.