Research On Key Techniques Of Vehicle Charge-discharge Storage Integrated Station Based On V2G

In order to effectively cope with the challenges posed by the energy crisis and environmental degradation,countries around the world are rapidly advancing the industrialization of electric vehicles,and the corresponding production and construction of electric vehicle charging facilities are also rapidly following up.The two-way converter of the electric vehicle and grid interaction(Vehicle to Grid,V2 G for short)as the core device of the charging,discharging,storage and integration power plant can not only solve the problem of charging for long-distance running of the electric vehicle,but also can reduce the load on the grid of the electric vehicle.The peak filling function has important theoretical research and application value.Firstly,this paper proposes a two-level topology of V2 G bidirectional converters.The former adopts a voltage-type three-phase half-bridge topology.The latter-stage circuit topology adopts a non-isolated Buck-Boost DC bidirectional conversion structure.The working principle of the topology structure,and established a mathematical model.Secondly,the grid-connected control strategy of V2 G bidirectional converter is studied,a method for judging three-phase phase sequence is proposed,an all-digital phase-locked loop based on d-q transformation is designed,and the working principle and basic principle of phase-locked loop are analyzed in detail.Make up the module.Then,by establishing a mathematical model of the three-phase SVPWM rectifier in the α-βand d-q coordinate system,a double closed-loop three-phase rectification control strategy based on α-βcoordinate transformation and current feed forward decoupling is studied.Different control strategies are implemented on the Matlab/Simulink platform.A simulation analysis was performed and the simulation results showed the effectiveness of the control strategy adopted.Finally,aiming at the complexity of filter parameter design of grid-connected V2 G converters,a filter parameter optimization design scheme with minimum total inductance under the premise of ensuring filter performance is proposed.The influence of various parameters of the LCL filter on the filter performance is compared and analyzed in conjunction with the three-dimensional map.According to the constraints of the harmonic content at the switching frequency,the relationship between the filter parameters and the filter performance is quantitatively described;the graphical method is used to determine the minimum total inductance.For the purpose of the filter parameters,and using different combinations of filter parameters on the TMS320F28335-based hardware platform for comparison experiments,the experimental results show that the optimal design of thefeasibility of the program,verifying the control strategy of the bidirectional converter based on V2 G technology And filter optimization program is correct and effective.