Modular solid-state transformers (SSTs) are suitable for various voltage- and power-level applications.State-of-the-art modular-SST topologies contain a considerable quantity of high-frequency transformers (HFTs) and power switches, thereby increasing the costs, difficulty, and workloads of engineering.To overcome this challenge, a new SST topology family, namely, hybrid-frequency cascaded full-bridge SST (HCFB-SST), is established on the basis of 355 maybelline fit me the concept of hybrid-frequency modulation.In comparison with modular-multilevel converter SST (M2LC-SST) or CFB-SST, the HCFB-SST uses only 50%-66.
7% and 1.11%-10% the device count annie brocoli dvd of power switches and HFTs, respectively, in typical applications, thereby obtaining considerable cost savings.It also achieves a cost reduction of sub-module redundancy.In addition, HCFB-SSTs have simple engineering and compact structures.
A hybrid-frequency modulation method is proposed for a low well-balanced average switching frequency and a high equivalent switching frequency without monitoring the bridge-arm current.Analysis and comparison of the semiconductor loss with existing topologies are presented.The simulation studies are conducted to validate the effective function of HCFB-SST and the proposed modulation method.