Research On Control Strategy Of Battery Swapping Station In Microgrid Based On Full Battery To Grid

Nowadays,the contradiction between economic development and environmental protection has become increasingly prominent.Electric vehicles,clean energy,and microgrids have been greatly promoted by the government.The electric vehicle battery swapping station can be integrated to microgrid as a special energy storage system.The battery to grid(Battery to Grid,B2G)interaction technology can realize optimal operation of microgrid and battery swapping station,which can reduce the interactive power fluctuation of the tie-line and reduce the impact on the distribution network caused by microgrids,and improve the power quality of the microgrid,and increase the revenue of battery swapping stations.In this context,this paper has carried out related research,and the main contents are as follows:This paper summarizes the advantages and disadvantages when the battery swapping station chooses charging battery,waiting for charging battery,and full battery respectively to provide B2G service.A new full battery to grid operation mode has been proposed.This mode can not only solve the problem of difficulty in making a charging plan caused by choosing charging battery and the energy-less caused by choosing the waiting for charging battery,but also can ensure high service reliability by adding dischargeable batteries.Based on the proposed full battery to grid mode,a model for day-ahead charging plan model is established which regards the number of batteries and SOC as the control variables.Meanwhile,we limit the maximum allowable value of power fluctuation between microgrid and distribution network in order to reduce the impact of the tie-line power fluctuation on the distribution network.The simulation results show that the proposed charging plan can significantly reduce the charging cost,cut the peaks and fill the valleys,and ensure the power fluctuations within the set range.Based on the proposed full battery to grid mode,a dynamic battery scheduling strategy is proposed to dynamically adjust the number of batteries used to provide swapping services and B2G batteries to ensure the reliability of battery swapping service and the availability of B2G service.The results show that the service reliability of proposed battery scheduling strategy is still high even when the error of demand forecasting is large.Taking the battery swapping station smoothing photovoltaic power fluctuation as an example,in order to analyze the effect and economics of providing B2G services for battery swapping station,we proposes 3 models and methods.They are the power distribution model of the B2G service,the calculation method of the discount rate when the dischargeable batteries provide the power exchange service,ana the calculation method of the revenue for B2G services.Finally,an example is given to analysis the effect and profit of providing B2G services for a battery swapping station.