| Along with the deteriorating of environment and the serious situation of energy,various countries in the world have seen the phenomenon that the problem of environment and energy restricting the sustainable economic development.The electric vehicle which has certain advantages in terms of energy consumption,not only could alleviate the pressure of oil using but also reduces the carbon dioxide emissions in China.The rapid increase of electric vehicle charging load put forward higher requirements to the output of power grid,power distribution capacity and safe operation.The influence of electric vehicle charging for grid mainly exists in the distribution network,at present, research mainly focus on distribution network planning, power quality and economic operation, etc.Study on the influence of distribution network is based on the charging load calculation and distribution. There are many influence factors of charging load calculation,including SOC(state of charge), start charging time, electric vehicle quantity and operation rules, etc.In many method of electric vehicle charging load calculation is according to the development trend of electric vehicle to determine its quantity,in stead of considering battery charging position in the peak of charging. Considering the charging during peak period,this dissertation uses the specific electrical position quantity instead of the electric vehicle number to obtain a more accurate consequence, the different functional areas of the electric vehicle parking numbers are different,and different people have different traveling purpose on working days and holidays lead to different functional areas of electric vehicle charging load characteristic are very different,by the method of Mamdani fuzzy logic reasoning and parking demand to determine the electric vehicle parking number in different functional areas,and take the number of parking Spaces as a qualification of the electric vehicle charging load calculation method which is based on monte carlo simulation to calculate the charging load of different functional areas.According to the calculated load curve to analyze charging load which influence in different function areas on working days and holidays,we can acquire peak-valley time and peak-valley difference of charging load.The electric vehicle charging load effect on the scheduling of distribution network research,such as a regional charging load calculation which effect on the distribution network,research on the influence of distribution facilities is less.The main equipment in the power distribution facilities is distribution transformer,we will calculate and analyze its life loss.This dissertation will combine the electric car loads in different functional areas,through the hot-spot temperature evaluation model of transformer life assessment model evaluation model (differential equation and difference equation)to calculate the distribution transformer life lost in different functional areas,and contrast analysis of each function area charging load influencing the loss of matching variable life and life lost time.According to the different function areas of the electric vehicle charging load on working days and holidays we can calculate charging load’s ratio of transformer capacity in peak period.To analyze the charging load’s influence of distribution transformer in peak time,we also consider the selection and expansion of distribution transformer.According to analyze charging load curve which influence in different function areas we can know the different nature of work and life in different function areas had a great influence on charging load.If we have effective measures of peak load shifting,we can improve the economic operation of distribution network.Superposition of electric vehicle charging load we can calculate the distribution transformer lost life and compared with the distribution transformer lost life which caused by basic load.The charging load’s influence of distribution transformer in different function areas,the influence of the residential area was the most obvious.Through the ratio of charging load in peak time with distribution transformer capacity,we can acquire conditions that expansion of distribution transformer. |
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