Research On The Impacts Of Electric Vehicles Charging And Discharging On The Power System

The increasing number of cars has led to a large number of exhaust emissions,causing serious pollution of the environment.In recent years, haze and other bad weather occurs frequently especially in the northern city,people begin to pay attention to environmental issues.Electric cars have the advantage of zero pollution,low energy consumption and so on.At present,all the countries in the world are studying the electric vehicle,and our government is no exception.When EVs industrialization development in the future,it will have a great impact on the power grid.The purpose of this paper is to explore the effect of electric vehicle charging and discharging on power grid and corresponding strategies are proposed.Fristly,we introduce the current research situation.On this basis, this paper uses the Monte Carlo method to set up the model of the electric vehicle’s travel chain and the charging and discharging load of private electric vehicle and electric utility vehicle are simulated by MATLAB.Power grid daily load curve of electric vehicle under different charging modes is obtained.It highlights the orderly discharge of superiority.Next,this paper used MATLAB to build a single and multiple electric vehicle charging and discharging equipment simulation model to study the power grid harmonics caused by EVs charging and discharging.The characteristics of harmonics generated by single and multiple electric vehicle charging and discharging are summarized.Laying the foundation for the following harmonic governance.This paper presents a parallel hybrid filter(PHAPF) control method for harmonic problems caused by large-scale electric vehicle charging.Firstly,we analyze the structure and working principle of PHAPF.We propose two harmonic detection method based on three-phase circuit instantaneous reactive power theory in HAPF control process:p-q andi_p-i_q.Aiming at the disadvantages of harmonic current detection methods such as small scope of application,using a non-PLL i_p-i_q algorithm to detect current harmonics.Due to the removal of the PLL this method makes the detection circuit greatly simplified,While eliminating the signal delay and deviation caused by PLL.Finally,this paper built harmonic governance model by using PHAPF under MATLAB.Simulation results show that the power grid current harmonics are declined greatly.Power quality is greatly improved and reached the required standards.