Communicationless Power Management Strategy for the Multiple DAB-Based Energy Storage System in Islanded DC Microgrid

摘要

Along with the development of the renewable energy such as the photovoltaics (PV) and the wind turbine (WT), the isolated dc microgrid with energy storage system is becoming as a promising candidate for reducing the fluctuation caused by the renewable system and providing stable energy to the power consumer in some remote application such as the deep mountain and the remote island. In this paper, the dual-active-bridge (DAB) dc-dc converter with bidirectional power flow ability, wide soft-switching range and ultrafast dynamic characteristic is adopted to establish an energy storage system (ESS) with multiple energy storage units (ESUs) for the isolated microgrid. In order to realize maintenance and extend capacity of the ESS, a communicationless power management strategy is proposed for this multiple-DAB-based ESS, and the high robustness of the dc-link voltage can be ensured when the input voltages and load conditions are changed, and even when an ESU is plugged-in or -out. Since the central controller is not employed, the reprogramming operation is not required, especially when the new ESU is plugged in. Finally, a small-scale experimental platform is employed to verify the effectiveness of the proposed communicationless management scheme.