A grid-connected robust control based on mixed sensitivity for AC/DC hybrid microgrid

Abstract

The grid-connected control technology of ac/dc hybrid microgrids affects power quality, stability, robustness, and other indicators. In order to achieve high-quality and reliability of ac/dc hybrid microgrids connected to a distributed network, this paper proposes a robust control method for grid-connected ac/dc hybrid microgrids based on mixed sensitivity. First, the grid-connected model of ac/dc hybrid microgrids is equivalent to the superposition theorem; then, the problem of how to control grid-connection can be transformed to the problem of how to deal with mixed sensitivity by considering the influence of the distributed network on ac/dc hybrid microgrids as a disturbance. Second, the grid-connected robust controller can be obtained by using the Riccati method repeatedly, which can ensure good nominal performance of the system and enhance the robustness of the system. Finally, the validity and feasibility of the proposed control method can be verified with three simulation conditions.