Research On The Impact And Countermeasures Of Large-Scale Electric Vehicles On Power Grid

In the current situation of energy and environmental problems prominent promotion of electric vehicles become an effective way to solve the above problems.As electric vehicles scale up,the issue of charging demand and the impact on the grid must be considered.It is an important basis for the large-scale development of electric vehicles to correctly analyze its influence and put forward reasonable optimization strategies and governance methods.Firstly,the harmonic generation mechanism of mainstream charging equipment is analyzed.The mathematical model was established by theoretical analysis and simulated on Simulink platform.The results show that electric vehicle charging must produce harmonics.With the increase of charging interference,the total harmonic distortion rate decreases,but still exceeds the national standard.At the same time,the effective value of harmonic current also increases,which will have a negative impact on the power quality of the grid.Secondly,different types of electric vehicles’ charging behavior is analyzed,a mathematical model is established.In order to predict the number of electric vehicles,an improved grey Markov model is proposed.Then,according to the research data of the research group,the charging load of various electric vehicles in the region is predicted.The results show that the charging load of EV has an obvious curve peak.Then,based on IEEE33 system,Newton-Rafson method is adopted to calculate the power flow.After that,the influence of the large electric vehicles on the grid is analysed with the results of the power flow.In accordance with the charging load of electric vehicles under different permeability,the load superposition curve is drawn,and the voltage bias and network loss are calculated and analysed.With the increase of the scale of electric vehicles,the voltage deviation is intensified and the voltage overrun phenomenon appears.Network loss intensifies,affecting the economic operation of power grid;The daily peak-valley load difference will increase,causing great pressure on the power network peak regulation.Finally,an orderly charging strategy is proposed on the basis of game theory.The optimal objective function of comprehensive benefit is established by analyzing the game relationship between charging stations and EV users under the premise of considering the incentive of peak power system regulation.The improved W-GA-SA-PSO algorithm is used to solve the problem,and the obtained load curve results verify the effectiveness of the strategy.The peak-valley difference of daily load can be improved to effectively reduce the influence of a large number of charging loads on the power grid.