System Integration and Hierarchical Power Management Strategy for a Solid-State Transformer Interfaced Microgrid System

This paper investigates, and for the first time presents, the system integration of a novel solid-state transformer (SST) interfaced microgrid system. Accordingly, a hierarchical power management strategy is proposed for this system to enable islanding mode operation, SST enabled operation, and the seamless transfer between two modes. The proposed power management strategy includes three control levels: primary control for the local controller; secondary control for the dc microgrid bus voltage recovery; and tertiary control to manage the battery state of charge. The proposed system architecture and control strategies are detailed in this paper and a lab test bed is constructed to verify the system performance. Finally, several typical case studies are carried out. The experimental results verify the proposed system and distributed power management strategy.