Bidirectional DC/AC converter for flexible distributed energy integration into AC microgrids

Introduction. This work focuses on the development of microgrids in remote areas, islands and regions frequently affected by natural disasters, particularly in Vietnam and other island countries in Asia. Problem. The converters perform direct and isolated energy conversion to AC or DC microgrids, which are distributed grids that integrate various distributed energy sources, including renewable energy such as wind power, solar power and others. To enable the system to operate continuously providing stable power, improving the efficiency and effectiveness of distributed power sources by providing a suitable circuit design to limit losses on the main switches and the number of switches and passive components in the converter is minimal. The goal is to develop the internal structure of a boost DC converter into a multi-port converter connected to the storage system and the AC microgrid under the condition of reducing the main switching losses with the condition of intermittent charging of the storage system during the operating period of the solar power source. Methodology. The study uses the switching adjustment method and modeling simulated to analyze the operating conditions adapted to the application system. Results. Analytical expressions were derived for calculating currents, voltages, losses on components, main switches, and conventional switches. The influence of storage circuit switching on reducing losses in the main switch is shown for the operating cases. Scientific novelty. Using the developed simulation model, new expressions were derived that allow us to establish operational dependencies that reveal the relationships between the parameters of the storage device’s switching components. These dependencies determine the efficiency and performance of the operational function, meeting the requirements of the microgrid system. Practical value. Enhance the efficiency of utilizing distributed energy sources and improve the conversion efficiency of flexible operation converters for AC or DC microgrids in the power system. References 30, tables 2, figures 22.