Engineering Theory Analysis Of Electric Vehicle Charger Access To Residential Power Grid

Electric vehicles have the advantages of small energy consumption and low pollution,which is of far-reaching significance for the sustainable development of energy,environment and economy.Electric vehicles are recharged by electric vehicle chargers.As a typical nonlinear device,electric vehicle chargers are bound to have a large negative impact on the power grid.And with the improvement of people's living standards,the types of household appliances have undergone tremendous changes,which not only lead to large deviations in the estimation of residential grid load,but also aggravate the harmonic problem of residential harmonics.In this paper,firstly,based on the measured cell data,the load distribution in every half an hour of the cell is calculated by using the peak probability distribution of power distribution,and the kernel density estimation method is used to fit the data of each time period to obtain the load demand of the cell Coefficient,the data obtained is more accurate than the current national standard data,the data can be obtained in the case of a certain supply capacity,as much access to the electric vehicle charging load.Through the study of living in electrical appliances,as well as harmonic statistics,the use of PSCAD software for different combinations of harmonic characteristics of electrical equipment statistics.On this basis,build a typical district distribution network model,to determine the unit distribution trunk and community harmonic value.Secondly,for the most commonly used three-phase uncontrolled rectifier charger and twelve-pulse rectifier charger,the harmonic characteristics of the uncontrolled rectifier circuit are analyzed theoretically,and then the charger simulation model is built according to the charging principle.Based on the district distribution network model and the model of electric vehicle charger,the influence of electric vehicle load on the distribution network of the district is analyzed.First,we get the number of electric vehicles that can be carried under the harmonic regulation,and the influence on the transformer load ratio,line load factor and voltage offset under different permeability.Finally,for the research question,put forward the feasible suggestion to the district distribution network that take into account the charging load of electric vehicles in the future.