Coordinated Charging Strategy For The Charging Station Of Electric Vehicles With Distributed Energy System

Distributed generations(DGs)and electric vehicles(EVs)have been in rapid development in recent years,while the uncertainty and volatility of generating and charging will have a detrimental impact on the grid.As a consequence,a strategy that can realize the local accommodation of renewable energy and coordinated charging of electric vehicles is needed.In this paper,the coordinated charging strategy based on time-of-use(TOU)charging price for the single charging station and the charging strategy based on TOU charging price for different stations in the same area were studied.At last,the optimal software for the coordinated charging strategy was designed and developed.For the case of single charging station,the price response model was introduced and the value of parameters was determined firstly.Then an optimal model of charging load was constructed which aims at improving the utility of photovoltaic and cutting down the peak load of the station.The constraint about capacity of the transformer and the peak-valley property of charging periods were considered.The particle swarm algorithm was used to calculate the property of coordinated periods and coordinated TOU charging price.Finally,the practical examples were optimized to verify the strategy.The problems of the strategy were analyzed.The improved coordinated charging strategy considering the state-of-charge(SOC)of electric vehicles was studied.The model of charging load and the transferred way of charging load were improved.Optimal results show that coordinated strategy obviously improved the utility of photovoltaic and cut down the peak load of stations.Furthermore,the optimal results were better after using the improved coordinated strategy instead of original coordinated strategy.For the case of multiple charging stations in the area,the main nodes of roads and locations of stations were established and the model of road network was constructed.Then the matrix of node-path was constructed and the Floyd method was introduced to calculate the minimum driving path and distance between these nodes.After that,the characteristic of charging load in the area were simulated.The optimal model of charging load between stations was constructed which aims at improving the utility of charging piles and reducing the charging cost of drivers.The constraint about number of charging piles and the SOC of batteries were considered.The particle swarm algorithm was used to optimize the charging price of different stations in each period.Finally,the practical examples were used to verify the effectiveness of the coordinated strategy.The simulation results show that the coordinated charging strategy between stations can improve the utility of charging piles in the station,as well as reduce the charging cost of users,which is beneficial to both vehicles and stations.