Adaptive normalized droop control for low-voltage hybrid microgrid interlinking converter

An adaptive normalized droop control strategy for the interlinking converter of the hybrid microgrid has been proposed in this paper. The standard normalized droop can realize bidirectional power coordination between subgrids. However, transmission power accuracy is low, and subgrid bus voltage varies from the rated value. The proposed control strategy avoids unnecessary power flow so as to achieve accurate power transmission and effective voltage deviation compensation. In this study, low voltage AC/DC hybrid microgrid is examined. It can be deduced from mathematics that the increase in droop coefficient can improve power transmission accuracy. The variation of AC/DC voltage is added to the operation criteria of the IC, which can reflect the load state, to prevent frequent action when the IC is close to the rated working condition. The state equation of the system is obtained by small signal modeling, and the upper limit of the droop coefficient is obtained by a stability constraint. Based on the preceding analysis, the adaptive normalized droop control method is designed to achieve accurate power transmission between subgrids. This ensures that the subgrid receiving power is kept in the rated state. Corresponding simulations based on MATLAB/Simulink and experimental results based on a hardware-in-the-loop platform have been illustrated. (c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under theCCBY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).