Economic Operation of Microgrid Containing Charging-Swapping-Storage Integrated Station Under Uncertain Factors of Wind Farm and Photovoltaic Generation

Direct microgrid-connection of electric vehicles(EV) makes no contribution to achieve the low-carbon electric power in its true sense, however, the microgrid-connection of EV via battery charging-swapping station(BCSS) to locally accommodate the electric power generated by renewable energy sources and combining BCSS with energy storage station(ESS) to constitute charging-swapping-storage integrated station(CSSIS) that is taken as the energy storage system for microgrid can reduce the impact of EV on microgrid operation, meanwhile the adjustable capacity of energy storage system can be increased. In allusion to the uncertainty of both wind turbines and photovoltaic(PV) generation inside the microgrid as well as the fluctuation of load, a chance constrained programming based economic optimization model, in which satisfying the reserve demand under a certain confidence level is taken as the reliability constraint and based on peak-valley TOU price the output of the integrated wind power station and the fuel cell is optimized and the interchange power of the tie line is determined, is established. When the charging/discharging power is allocated between BCSS and ESS, the sliding window method is utilized to adjust the charging/discharging of BCSS first of all, and then the remaining power is taken on by ESS, thus to create a stable operating environment for BCSS as well as to provide BSS a support with adjustable capacity. Taking a concrete microgrid for example, the effectiveness of the proposed strategy is validated.