Power converters for battery energy storage systems connected to medium voltage systems: a comprehensive review

Abstract

Recent works have highlighted the growth of battery energy storage system (BESS) in the electrical system. In the scenario of high penetration level of renewable energy in the distributed generation, BESS plays a key role in the effort to combine a sustainable power supply with a reliable dispatched load. Several power converter topologies can be employed to connect BESS to the grid. There is no defined and standardized solution, especially for medium voltage applications. This work aims to carry out a literature review on the main converter topologies used in BESS and highlight the main advantages and disadvantages of each one. The topologies used for each conversion stage are presented and their combinations are analyzed. In addition, the different services that BESS can carry out when connected to the distribution system are analyzed in order to demonstrate all the main contributions to the electrical systems. Finally, a case study is performed to compare and analyze the converter topologies for BESS, considering some aspects such as efficiency, power quality and number of components.