Probabilistic and Fuzzy Modeling of Charging and Discharging of Electric Vehicles in Presence of Uncertainties Applied to Unit Commitment Problem

Advent of electric vehicles in power systems has a variety of effects. The most important effect of electric vehicles in the power system, is related to increase of demand due to charging process (G2V) and also power injection to grid (V2G). In this paper unit commitment problem has been solved considering electric vehicles. Since charging and discharging of electric vehicles depends on factors such as electricity price, fuel price, the rate of charging and discharging as well as the overall behavior of car owners, to cover these uncertainties, both probabilistic modeling and fuzzy sets theory are used. In probabilistic modeling of consumption and generation of electric vehicle in each hour, the number of Evs, the rate and start time of charging and discharging process, and the average distance traveled by each Ev is considered. Since fuzzy modeling can be used in cases that historical data is not available, in second part of this paper a fuzzy number has been assigned to determine the power generation or consumption related to Evs in each hour which is need to solve unit commitment problem. A 10-unit IEEE test system is considered for simulation with 50,000 gridable vehicles using a hybrid GA-ICA algorithm and then the results of probabilistic and fuzzy modeling are compared with each other.