On the effect of DC source voltage on inverter-based frequency and voltage regulation in a military microgrid

Increasing concerns about energy security and reliability are intensifying the military´s interest in the microgrid technology. This paper focuses on the frequency and voltage regulation part of a case study that seeks to design a conceptual military microgrid that has to operate completely autonomously. This microgrid comprises a solar panel and vehicles as power sources, where the vehicles contain a battery and generator, and managing their power setpoints is the control problem of interest. The goal is to investigate the validity of assuming the battery as a constant voltage source during the control design. To this end, the control design is first carried out assuming the battery as a constant voltage source. It is then illustrated how critical this assumption can be depending on the battery internal resistance. The results show that the battery internal resistance can affect both frequency and voltage regulation performances, thereby highlighting the coupling between the battery characteristics and control design, and the need for a control design framework that takes this coupling into account.