Optimal Discharging Strategy in Electric Vehicle Charging Stations with Particle Swarm Optimization

Due to "Zero Emission" and "Low Noise", Electric Vehicles (EVs) have been regarded as an important way of reduction in the carbon emission and the protection for environment. Moreover, the penetration of EVs into power systems not only can reduce energy loss and lessen emission, but also can provide ancillary services for improving power quality, shaving peak load, etc. Given this background, according to key technology and demonstration engineering of many countries, such as USA, Japans and Europe, the status of EVs’ research and promotion at home and abroad were analyzed in detail. Then, the three kinds of EVs applied widely at present were respectively presented to identify their advantages and disadvantages as well as the concept of V2G. Given this background, a mathematical model for optimizing discharging strategy in EV charging stations is developed and solved by particle swarm optimization (PSO) with the maximization of the total operating income of the EV charging stations as the objective function, and some operating limitations as constraints to be respected. Finally, IEEE 34 node test feeder is applied to illustrate the feasibility and effectiveness of the developed model.