Comparison of Different V2G Configurations for A Microgrid System in Terms of Different Ancillary Service Controls

A microgrid system able to supply 15 households was established in Xiaolin Village in Taiwan. Each house consists of 3kW solar photovoltaic panels and 6–10 kWh battery modules. Moreover, a 100 kWh energy storage container (see Fig. 1) is installed for power balance. As the number of electric vehicles (EVs) in Taiwan gradually increases, the batteries of these EVs become important resources for grid operations. Therefore, it is crucial to explore technologies like Vehicle-to-Grid (V2G) and Battery-to-Grid (B2G) and how they can be implemented in the Xiaolin microgrid. The chargin station needs to be carefully designed so that it can well coordinate with existing energy storage and PV systems. The objective of this paper is twofold. Firstly, some of the ancillary service control functions will be implemented in inverters to achieve either V2G or B2G. Secondly, we will investigate two types of configurations that V2G or B2G can be implemented in the Xiaolin microgrid and see which one has the best contribution to the grid. From the results presented in the paper, we can conclude that a centralized inverter, capable of providing V2G services, EV charging, power conversion, and balancing can offer a cheaper and coherent control performance. Nevertheless, efforts needs to be devoted to keep the centralized inverter to maintain operational for system reliability.