The Power Distribution System Planning Of The Community With Electric Vehicle Charging Facilities

In this paper,by constructing a community model and a community distribution model,we establish mathematical models for residential electricity consumption,public electricity consumption and electric vehicle charging respectively,and the daily load of the community and the capacity and quantity of the community transformer are analyzed and planned.For the residential power load,considering the variety of household electrical equipment,such as lighting,television,washing machine,kitchen appliances,etc.,the unit index method is used to calculate the load by combining the influencing factors such as residential area and average household load,and adding the simultaneous coefficient to refine the consideration.For the public electricity load,considering the various public facilities in the area,such as public lighting,elevators,domestic water pumps,etc.,use the demand coefficient method to calculate the load in combination with the power of different equipment.For the electric vehicle charging part,the load value is calculated by considering the combination of household penetration rate,average household ownership and charging post power.For the distribution system,it is necessary to consider the various impacts of EV access system charging on the distribution network,such as harmonics,network loss and so on.It is also necessary to find a solution to improve the problem at the root.The orderly management of charging facilities is implemented on the consideration of the economy of installing charging facilities in the cell,the utilization efficiency and the load fluctuation of the cell distribution system.Firstly,the optimal splitting distance method is used to optimize the orderly queuing charging strategy,which improves the situation that charging is not allowed in peak hours in the original orderly charging strategy,and introduces a limited power σ,that is,when the user’s vehicle is connected to the community system to charge in peak hours,the car can be fully charged under the condition of ensuring the stability of the community load fluctuation and the satisfaction of residents In this paper,σ is set to 0.9.Different types of cells can set the limit value according to the specific situation.In order to make the division of charging periods more flexible and accurate,this paper also introduces the grid division method combined with the orderly charging in the normal period,through the formulation of adjustable charging power,to realize the optimization of the charging queue scheme in the normal period.The specific method is to reduce the power supply of the charging facilities when the cell load value reaches the set value in the normal period,this paper sets7 KW and 5k W.The optimized peak,level and valley periods are combined with simulation again to find an orderly charging queue scheme suitable for the planned cell.The simulation results show that after changing the charging rules,the power supply pressure of the distribution network in the community can be alleviated to a certain extent,while ensuring the charging satisfaction rate of residents,reducing the standard deviation of the community load,making the load fluctuation of the community more stable,solving the contradiction between the supply and demand of charging facilities and electric vehicles,making it more practical.Finally,the distribution system of the planned community is analyzed in detail.The type and location of transformers,the wiring of low-voltage power distribution systems,lightning protection devices and grounding systems,as well as the installation characteristics and requirements of electric vehicle charging piles and the safety protection of charging facilities,combined with the optimized orderly charging queuing strategy,to find a more suitable power distribution system arrangement for cell transformation and construction,for further implementation of Optimization of power distribution systems in new and old communities and formulation of related management rules provide construction advice,and also provide a realistic basis for future orderly charging queuing strategy improvement and research on the impact of charging behavior in the distribution network.