Research On Harmonic Analysis And Suppression Device Of Electric Vehicle Charging Station

In order to solve the problems of fuel vehicles consuming energy and polluting the environment,countries around the world have begun to vigorously promote the development of electric vehicles.Electric vehicles can store electrical energy in energy storage units,and can provide electrical energy for motors during driving to achieve zero emissions,clean and efficient,Widely popular in the automotive market.However,subject to the endurance of electric vehicles,a large number of charging stations must be provided for electric vehicles to solve the charging problem of electric vehicles.At present,charging stations are generally installed in urban areas and high-speed servers in China,but the charging stations themselves exhibit strong nonlinear characteristics,resulting in a large amount of harmonic currents during operation,which harms the operation of regional power grids.The active power filter(APF,Active Power Filter)can dynamically compensate for harmonics in the power grid,but due to the lack of experience in the use of APF in the power grid,and the current APF has many defects in the control algorithm,it needs further improvement This article will design the APF and use the charging station studied in this article as a pilot to provide experience for the grid to control harmonic problems.In the research process of this paper,first of all,a detailed analysis of the current status of the power grid,through analysis,to understand the current reactive voltage operation of the power grid,and then proposed to use APF to compensate the reactive power of the power grid.Secondly,the basic structure and working principle of APF are analyzed.By analyzing several existing topological structures of APF,the parallel voltage APF structure with superior performance is selected as the research object of this paper.The APF is modeled,and After comparing and analyzing the common pq method and dq harmonic current detection method of APF,the defects of these two methods are pointed out,and then an improved dq method is proposed to carry out harmonic detection,thereby improving the compensation accuracy of the system,and at the same time The control strategy is designed.In the outer loop voltage control process,fuzzy control technology is used to improve the problems caused by the traditional PI control algorithm in controlling the nonlinear system.In the current inner loop control process,in order to reduce the difficulty of the system control,Performing decoupling control effectively simplifies the complexity of algorithm control.In the process of PWM modulation,in order to solve the problem that harmonics are easily generated in the modulation process of the traditional SVPWM algorithm,a double random SVPWM control algorithm is used to achieve APF modulation,thereby improving the quality of power,and the simulation verifies that the designed algorithm It can accurately achieve APF reactive power compensation.Finally,the software and hardware system of the APF are designed to realize the specific functions of the APF,and after the device design is completed,it is put into operation in the charging station.Through the role of the APF,the harmonic current of the charging station is managed to improve The power factor and voltage quality of the system bring good economic and social benefits to the operation of the power grid.