To study the influence of large-scale plug-in electric vehicles (EVs) on the power grid

a bi-level economy dispatch optimization model based on vehicle-to-grid (V2G) is presented. Based on the traditional security constrained unit commitment

the spatial and temporal distribution characteristics of electric vehicles are also taken into account. The model is then separated into two sub-models

i.e. the unit commitment model and the EV charging and discharging scheduling model. The model can be solved by the particle swarm optimization algorithm and the linear programming algorithm based on the Newton-Raphson power flow algorithm

Results show that the next-day unit commitment scheme and electric vehicle best charging and discharging schemes of each time interval are obtained through the model proposed. Furthermore

this model can realize real-time optimal control during 24 hours and allot the V2G dispatch plan to each access node spatially

which is instructive for the layout of the charging station. It can reduce network loss and the peak-to-valley load difference at minimal generation cost.