Design Of Photovoltaic Charging Station And Battery Charge And Discharge Scheme

The increasing reduction of fossil energy and the environmental problems brought about the rapid development of various fields have made the development and research of new energy an inevitable trend.In this field,solar electrical energy generaiton and electric vehicle have been well developed,the combination of the two that is the photo-voltaic charging station of electric vehicle which is the realization of electric vehicles on renewable resource for local utilization of typical integration mode.The construction of PV charging station not only achieves no pollution at all,but also extends the electric vehicle's journey.It has the advantages of no site restriction and adjustable capacity.The solar photo-voltaic power generation will be affected by natural conditions.It is necessary to use energy storage technology to solve the problem of randomness and volatility in the process of generating electricity.The energy storage part is storage battery that controls the bidirectional DC/DC converter through microprocessor and some functional chips and auxiliary circuits,so as to realize the flow of energy,which is the charge and discharge of the battery.On the other hand,a suitable charging and discharging scheme can prolong the service life of the battery and improve its utilization efficiency,and then reduce the overall cost.In this paper,the design scheme of photo-voltaic charging station and battery charge and discharge energy,firstly,makes the modeling and simulation analysis of the solar panel,and the appropriate maximum power point tracking method is selected to make the PV array provide power to the system at maximum power,then controlling bidirectional DC/DC converter for the storage battery charge and discharge,finally,completing the design of the related hardware circuit.The specific content of this article is as follows.The overall structure of the photo-voltaic charging station system is briefly introduced,and the functions of the components are explained.The output characteristic equation of the photo-voltaic cell is deduced,and the mathematical model of the photo-voltaic cell is set up,and the simulation is given.The principle of the most mature method of disturbance observation and the advantages and disadvantages of the method are described.In order to make MPPT have better dynamic performance,we choose the optimal gradient method to track the maximum power point.This method not only has good dynamic performance,but also has the advantages of automatically adjusting search step and automatically determining the direction of search.And the optimal gradient method is also simulated.In view of the energy storage part of the whole system,this paper briefly introduces the current development of the battery and the performance and characteristics of several commonlyused batteries.For distributed generation systems,lead-acid batteries are more suitable for this system through comprehensive analysis.However,the service life of battery will be affected by charging and discharging process,and the suitable charge and discharge plan can reduce the damage to the performance of lead-acid battery,thereby prolonging the service life of lead-acid battery and reducing the overall economic cost of the system.The charge discharge process is simulated on the basis of the selected charging and discharging scheme.Finally,the main parts of the system are selected and designed.The main circuit of realizing MPPT,the driving circuit of the switch tube,the voltage detection circuit and the current detection circuit are designed.Selecting microprocessors,the corresponding pin planning is illustrated.The circuit of bi-directional DC/DC converter to realize charge and discharge,the chip of IGBT in the drive circuit and the CAN communication circuit are selected.