Large-scale electric vehicles (EVs) integration into charging station disorderly will not only cause "peak load overlap" in distribution network, but also cause charging congestion and increase the waiting time of EV. A bi-layer optimization model for coordinated charging of EV charging station considering multiple charging modes is established. In the upper model, the objective is to minimize the variance of load and dispatch plan deviation between upper and lower levels, so as to achieve peak load shifting, and make the load curve flatter. In the lower model, a charging station queuing system based on multi-queue and multi-server is established to minimize the travel time and charging cost of EV. This paper proposes Genetic Algorithm (GA) and Ant Colony Optimization (ACO) to solve this problem by hierarchical iterative, the simulation is carried out in IEEE 33 node distribution system with four charging stations. By comparing with un-coordinated charging and Active Scheduling (AS) model, the results show that the proposed model is effective in optimizing distribution system load, reducing travel time and charging cost of EV.
