| With the increasing use of fossil fuels,the energy crisis and pollution problems have become more and more prominent,and the microgrid system with wind power,photovoltaic and other clean energy as the main forms of energy supply has become the focus of attention.At the same time,with the promotion of low-carbon travel,electric vehicles(EV)have become a good substitute for traditional fuel vehicles,and non-operating electric vehicles have shown a large-scale development trend.However,the randomness of its charging will pose a challenge to the energy supply configuration on the power side of the microgrid.Therefore,for the stochastic demand power increase and grid fluctuation increase caused by large-scale non-operating electric vehicles connected to the microgrid.This paper deeply studies the change of charging load caused by the change of non-operating electric vehicle penetration rate and the energy scheduling problem after the high penetration non-operating electric vehicle is connected to the microgrid.Firstly,by analyzing the historical data of non-operating electric vehicles,the distribution of charging time and daily mileage in different periods is obtained.Then the travel characteristics and charging laws of non-operating electric vehicles are obtained by fitting,and the charging model of non-operating electric vehicles is established.The working principles and mechanisms of wind power generation,photovoltaic power generation,energy storage system and micro gas turbine are analyzed in detail.Then through the correlation analysis,the number of public charging facilities,per capita disposable income,per capita consumption expenditure,the growth rate of investment in the secondary industry,and the total number of non-operating vehicles are identified as the main influencing factors of non-operating electric vehicle ownership.The Optimized Grey Prediction Model(GM(1,n))is used to predict the change of non-operating electric vehicle ownership,and the penetration rate in different years is obtained.At the same time,it is found that the permeability is gradually developing towards high permeability.The Monte Carlo method is used to solve the charging model,and the charging load under different permeability is obtained.It is found that the peak valley difference of electric vehicle charging load under different penetration rates is large,and the voltage fluctuation caused by the high penetration non-operating electric vehicles connected to the grid is analyzed through ieee33 node.Then,a scheduling model with the optimal objectives of minimum comprehensive operation cost,minimum charging and discharging of energy storage and optimal environmental benefits is established.Since the scheduling model belongs to the problem of solving high-dimensional(three-dimensional and above)objective function,an improved non dominated genetic algorithm 3(NSGA-Ⅲ)is proposed to solve it.The improved algorithm is mainly reflected in overcoming the limitations of the original algorithm to increase the diversity of species and the global search.Compared with MOPSO,NSGA-Ⅱ and NSGA-Ⅲ by using test function,the improved NSGA-Ⅲalgorithm is superior to other algorithms in distribution,diversity and convergence.Finally,the parameters of the microgrid system are simulated and set.According to the different operation modes of microgrid and considering the access of high penetration non-operating electric vehicles,four different scheduling strategies are formulated.The improved NSGA-Ⅲ algorithm is used to solve different scheduling strategies,and the configuration scheme and optimization target value results of micro sources in microgrid under different scheduling strategies are verified and analyzed by simulation.The results show that the load fluctuation caused by microgrid connected to high penetration non-operating electric vehicles in grid connected mode is significantly smaller than that in off grid mode.It also shows that microgrid is more economical in grid connected operation mode. |
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