Modeling and Experimental Evaluation of Energy Storage Emulator for Microgrids Application

The increasing of renewable energy sources (RES) in the global energy matrices follows the tendency of environmental sustainability, in alignment with the growth of the smart grid concept. Considering the impacts related to the RES intermittence, future perspectives on energy storage systems (ESS) are presented as promising solutions. Usually, ESS have a substantial price, and the laboratory tests may damage the energy storage devices' lifetime. Considering this scenario, this article presents the modeling and experimental setup of an ESS emulator. The proposed emulator's advantage is that only the ac utility grid and a voltage source converter (VSC) are required to obtain a dynamic response that reproduces an ESS dynamic behavior. Hence, the developed emulator may be easily reproduced with commonly found equipment in any electrical engineering laboratory. As a possible scenario of application, a dc microgrid is implemented. The microgrid is composed of a PV solar system, the ESS emulator, and a customer load. The ESS emulator evaluation is performed by comparative analysis between mathematical simulations and experimental results. The results showed that the ESS emulator presents high representatives when compared to the ESS mathematical model, with an average error of 0.4%. This behavior is experimentally corroborated in the implemented microgrid application.