Energy management and control strategy of DC microgrid based hybrid storage system

In this paper, a method of energy management shared with storage devices in a standalone DC microgrid is presented. The objective of management is to satisfy the energy demand in addition to guaranteeing a production/consumption balance with good regulation and stability of DC bus voltage. Another advantage of the energy management method lies in the consideration of losses in the static converters by calculating the effective power available on the common DC bus. The proposed control strategy takes advantage of non-linear control by combining fuzzy logic control for the extraction of the maximum power from the photovoltaic and wind sources, while sliding mode control is used for the control of the storage power converters. The control of the power flow of the common DC bus allowed good stability of the bus voltage with small deviations around the desired value, limiting the battery stress since the low-frequency current component is sent to the battery while the higher-frequency power component is directed to the supercapacitor. The simulation results show the validity of the proposed energy management and control strategy.