Power electronic transformer in addition to the traditional transformer functions, also has the advantages of power flow control, power quality regulating and maintaining the system stability, can meet the demand of the development of smart grid in recent years, received a great attention. This article reviewed the development of several key technology of PET. First of all, introduced to the PET research necessity and principle. Secondly, a careful analysis of the present stage of PET topology . Thirdly, through the typical control strategies are summarized, it is concluded that the essence of its control, and establishes the mathematical model and the corresponding control method. Then analysis several schemes of the PET function expansion and its application field, finally summarizes the development situation of PET at home and abroad, and its development in future. This paper aims to summarize research on power electronic transformer, hope to provide reference value to the study of the field.
