The Key Parameter Method for Flexible-AC-Port Solid-state Transformer

The Flexible Interconnection Hub Station (FIS) has been proposed to address issues such as node voltage deviation, increased network losses, and growing peak-to-valley differences in loads caused by the large-scale grid integration of new types of sources and loads within distribution networks (DNs). Furthermore, a FIS topology based on the cascaded H-bridge type solid state transformer (CHB-SST), and the Flexible-AC-Port SST (FACP-SST), are introduced to meet the power flow regulation needs under multiple feeder conditions. Compared with traditional solutions, the FACP-SST offers a more economical and convenient port expansion. The FACP-SST is a series-parallel type topology, with the series part serving as the channel for power exchange between FACP-SST feeders. By altering its output voltage, it regulates the series voltage between feeders to control feeders power flow. The quality of its parameter design directly affects the operational characteristics of the FACP-SST. Therefore, this paper presents a series voltage design method for flexible-AC-port solid state transformers to fulfill the requirements of device design.