Research On Operation Optimization Of Large Scale Electric Vehicle Access To Distribution Network

With the rapid development of electric vehicle(EV)technology,and the country's support for EV industry,EVs is bound to large-scale operation in the future.A large number of EV cluster charging will bring great pressure to the operation of the power grid,so the study of an effective charging control strategy for the economic operation of the power grid has a positive significance.Firstly,the driving habits of various types of EVs are analyzed,and the probabilistic models of the start charging time and the initial SOC are established.Monte Carlo method is used to simulate the charging load curve of all kinds of EVs.The IEEE33 node distribution network as an example,the influence of different permeability EV charging on distribution network is simulated.The results show that with the increase of the permeability,the peak load,peak-valley difference is gradually enlarged,the voltage variations is increased,and the network loss rate is also increased slightly.Secondly,the fuzzy clustering algorithm is used to divide the load curve into two periods:peak and valley.With the objective function of minimizing the user's charging cost,the start charging time of each EV is the control variable,and the multi-population genetic algorithm(MPGA)is used to solve the optimization model.The results show that the charging strategy can play a good effect of peak shaving and valley filling,improve the voltage level,reduce the network loss rate,and realize the safe and economical operation of the distribution network.Finally,the response ratio of the user to the TOU under the stimulation of electricity price is analyzed.Considering the interests of both the power supply company and the users,a multi-objective optimization model is proposed to minimize the peak-valley difference and maximize the satisfaction of electricity consumption.The NSGA-II algorithm is used to solve the optimization model.The results show that the TOU scheme can fully guide the user to charge in valley period,and achieve the goal of effectively reducing the impact of charging load on distribution network.