A Cooperative Power Flow Control Strategy for Low-Voltage DC Microgrid Clusters

Hierarchical control strategies and active power flow controllers represent distinct approaches aimed at enabling flexible power distribution among different dc microgrids within a cluster. To enhance reliability and responsiveness in the face of uncertainties, particularly leveraging intermittent power flow control (IPFC), this article introduces a cooperative power flow control strategy. This method integrates an active interlinking converter featuring hysteresis control into traditional hierarchical control frameworks, activating the IPFC strategy in response to significant reference changes or uncertainties and naturally ceasing upon achieving convergence goals. This approach not only leverages the structural benefits of traditional hierarchical control but also mitigates its inherent response to uncertainties, which can be critical in dynamic operational scenarios. Importantly, it minimizes the need for large-scale, high-cost components and avoids additional switching losses typical of traditional power flow controllers. Furthermore, the proposed strategy is enhanced through the implementation of a virtual closed-loop control methodology, promising accelerated convergence rates and heightened operational reliability. Theoretical insights are validated through both simulation studies and experimental demonstrations using a hardware prototype.