Impact Of Electric Vehicle Charging On Distribution Network And Countermeasures

With the continuous consumption of primary energy,the energy crisis and environmental pollution are becoming more and more serious.Countries around the world have begun to invest in the research and development of renewable energy.Electric vehicles will replace traditional fuel vehicles as the main transportation tool in the future.However,as large-scale electric vehicles are connected to the grid for charging,they will have negative impacts on the power quality of the power distribution system,such as line overload,and the safety and economics of power distribution equipment.If we take reasonable control and scheduling of charging behavior of electric vehicles,as a mobile energy storage unit,the negative impacts on the distribution network can be significantly reduced.This paper predicts the future development trend of electric vehicles,studies the impact of electric vehicles on harmonic characteristics,load characteristics,network loss,voltage offset,and operation economics of distribution equipment during disorderly charging,at the same time,forwards the harmonic control method and orderly charging strategy.According to the statistical data and the electric vehicle charging characteristics model,the daily load prediction of different types of electric vehicles can be achieved by establishing different types of electric vehicle charging load models,and using neural network algorithm and Monte Carlo algorithm.By comparing the daily load characteristics of different types of electric vehicles,it is found that the impact analysis and optimization research on the charging load of private cars affect the trend of the total load curve of electric vehicles.The power characteristics of single and multiple electric vehicles at different charging stages are studied,the harmonic characteristics of the electric vehicle charging process and its generation principle are analyzed,and at the same time,principle and harmonic characteristics of the uncontrollable charger and the PWM fully-controlled charger are studied.A simulation model of electric vehicle charging was established through the simulink platform,and the harmonic characteristics of electric vehicles at different charging stages were obtained.In order to effectively suppress harmonic pollution,corresponding harmonic control measures were proposed.The load characteristics of large-scale electric vehicles after they are connected to the distribution network are studied.In the case of different penetration rates of electric vehicles,a 27-node power distribution system is used as an example.The harmonic current,network loss,voltage loss rate,and load fluctuation rate are analyzed.The research results show that large-scale disorderly charging loads will have a certain negative impact on the service life of power distribution equipment,the quality of power output from the power distribution network,and the safety and stability of power distribution equipment operation.In order to reduce the adverse impact of large-scale disorderly charging loads on the power distribution system,taking a large charging station as an example,considering the safety of distribution equipment operation,user charging requirements,and the characteristics of the superimposed load,an electric vehicle charging model with optimal power distribution is proposed by introducing the time-of-use electricity price mechanism.An optimization model solution method and an orderly charging control process are also proposed.Finally,an example analysis is performed to compare the results of the orderly charging and the orderly charging.