Microgrid topology for different applications in Vietnam

This paper proposes a common microgrid including distributed energy resources (DER) like diesel generation, photovoltaic cells (PV cells), wind turbine or other renewable energy sources (RES), an energy storage system and both ac and dc loads. This micro grid topology is applicable to various areas such as city buildings, a factory, a household, a small village or a rural farm. Case study for several areas will also be presented in this paper. For different cases, depending on the strength of the utility grid, the number of available DER and user convenience, ac, dc or hybrid microgrid can be applied. To improve the reliability of the microgrid, an energy storage system made of batteries connected in series is established to support the bus voltage immediately when the microgrid is disconnected from the main grid and when in stand-alone mode. This energy storage system can be charged from the main bus voltage through a converter. Overall, the microgrid is controlled by a microgrid control center. As an example, establishment and operation of microgrid for a rural farm will be shown.