Research On AC/DC Converter Of Charging Pile And Its Control Strategy Based On V2G

In recent years,the state has paid more and more attention to ecological and environmental protection and has received tremendous support for the development of new energy vehicles to replace traditional fuel vehicles.Electric vehicles,as the most popular environmental protection vehicle in the current era,have experienced tremendous growth in the market.The energy storage unit of an electric vehicle is both a load for the grid and energy for the grid.V2G(Vehicle to grid)has also been proposed,V2 G technology in the electric vehicle and the grid can achieve two-way flow of energy to help the grid shift the valley filling and stable grid operation.Therefore,the charging pile capable of realizing bidirectional flow of electric energy is the key.Therefore,it is of great significance and value for the research of the AC/DC converter in the charging pile.In this context,this paper studies the AC/DC converter and its control strategy in V2 G technology.This article first briefly introduces the V2 G technology and analyzes and compares the topology of AC/DC converters used in V2 G technology.The topology of AC/DC converter with voltage-based singlephase full-bridge topology is selected,and the two working modes under bipolar modulation are analyzed.The theoretical analysis is completed and the mathematical model is established as a control strategy.The study provided the basis.Then,the principle of the instantaneous current control control strategy used in AC/DC converter is analyzed and improved.The voltage loop is used as the PI part,and the PI current loop control is improved to be the quasi-PR control to improve the control strategy.The voltage zero-crossing distortion problem achieves no-quiet-tracking,enhances the tracking of the ac current signal without error,and reduces the harmonics of the output current.In order to better implement the feed link in the V2 G technology,improvements have been made to the phase-locked loop to eliminate the effects of power grid fluctuations.Matlab/Simulink was used for the simulation study.The voltage and current of the grid side was phase-inverted during charging,and the anti-phase voltage and current of the grid side during the discharge reduced the harmonic component of the output current.It is verified that the system has good dynamic performance during charge and discharge.According to the feasibility of the simulation,the hardware of the system was designed and constructed,and the related physical experiments were completed.