Research On Charging Technology Of Energy Storage System In Photovoltaic System

In the context of environmental pollution and energy resources in the growing tension,solar energy as a new type of green and renewable energy has been paid for more and more attention.The most attention focuses on photovoltaic.To ensure the normal operation of photovoltaic power generation system,energy storage is indispensable.At present,the bulk of energy storage devices are VRLA batteries.Because of its high charge control request,the research on high-performance VRLA battery charger is very important.Firstly,this paper analyses the characteristics of VRLA battery and current charging methods.An optimized five-stage charging method is proposed,and the charging simulation model with BUCK circuit as the main circuit is established.The simulation validates that the proposed method is feasible and effective.Secondly,for the photovoltaic power output instability and other issues,the paper studies the dispatchable grid-connected PV systems.Bi-directional DC/DC converter as the main control circuit,a practical stability control strategy is presented,and by simulation to verify.The results show that the proposed control method can effectively stabilize the PV system output power fluctuations and the DC bus voltage,meet the requirements of battery charge and discharge,and increase charge speed.Finally,the software and hardware system are designed in view of the proposed charging method.