Centralized charging power distribution method for electric vehicles

The extra electricity load generated by the increasing number of electric vehicles (EV) may have an adverse effect on the electrical grid of cities. At the same time, electric vehicles may also be considered as mobile energy storages that can significantly reduce load fluctuations. Therefore, a mathematical model for the coordination of EV charging and electric network capacity had been elaborated. The model supports the optimization of electricity load by charging power distribution and bidirectional energy flow between EVs and charging infrastructure. The optimization problem was solved using linear programming. The model was applied to determine the optimal solar power for charging EVs. It was found that daytime charging demand may be served using only solar energy without surplus in generation if the share of flexible demand was higher than app. 15 %. Furthermore, centralized control may decrease the charging cost significantly.