Overview and design of solid-state transformers

The SST has several advantages when applied in the modern electric distribution grid. Among them, the availability of the dc link for connection of dc microgrid is mentioned in this chapter. There are many different possibilities to implement the architecture of the SST, and an overview and classification have been presented. For electric distribution, the three power processing stages architecture is cited to be the best choice, because it provides the decoupling between the MV side and LV side and also providing dc link connectivity. Furthermore, the dc-dc stage plays an important role on the SST architecture design, because it is responsible for the major losses of the system, besides to be in charge for controlling the LVDC link. Therefore, the SRC and the DAB have been pointed out as the most promising choice. The SRC can provide a very high efficiency, but it is not able to control the power flow and the regulate the LVDC link properly. The DAB converter, on the other hand, can provide a high efficiency solution and provide full control. The design aspects of the power stage and control stage of the DAB converter focusing on the SST application has also been discussed in this chapter.