Cooperative Control of DC Microgrid Cluster with Different Voltage Levels

Abstract

A multi-voltage level DC microgrid cluster electrical connection architecture and cooperative control method are proposed in this paper, i.e., multi-port converter (MPC) is used to construct the power flow paths among microgrids, and load sharing and voltage deviation are optimized by the secondary control and tertiary control of the DC microgrid cluster. The secondary control is based on the proposed electrical connection architecture and adopts an improved distributed consensus algorithm, which improves the estimation accuracy of the voltage observer and solves the problems of voltage deviation and power distribution imbalance in traditional droop control. Meanwhile, the power flow among microgrids is coordinated by the tertiary control to realize mutual assistance of multiple microgrids of different voltage levels, which improves the consumption of new energy and the robustness of the microgrid cluster. Finally, the proposed method is verified by simulation.