Optimization of charging sequence of plug-in electric vehicles in smart grid considering user´s satisfaction

There has been an increase in penetration of renewable energy in recent years. However, due to the intermittency of renewable energy, there are several problems faced by the power systems such as system frequency fluctuation, surplus power and voltage rise on distribution feeder. The battery inside the electric vehicle (EV) is expected to be one of the devices which will be able to solve the above problems. In this paper, four EV charging schemes are considered: first come first serve schedule, sequence of existing state of charge (SOC) in ascending order, grid connecting time sequence, and sequence with the ratio of ?SOC to grid connecting time. The most suitable method is selected every minute based on the constraints. The result shows the flexibility of new charging schedule, and the users´ satisfaction index, which is defined as the ratio of charged energy to the required energy. The charging on the next day is also considered.