1.State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University,Xi’an710049,China;2.Shaanxi Key Laboratory of Smart Grid, Xi’an Jiaotong University,Xi’an710049,China;3.School of Electrical Engineering, Xi’an Jiaotong University,Xi’an710049,China

Intelligent distribution transformer is a key device to construct the new generation of intelligent distribution network with the rapid development of smart grid. This paper analyzes the main functions of the intelligent distribution transformer combining the development trend of the distributed generation of renewable power and AC/DC hybrid distribution power system, and states that the key of realizing the intelligent distribution transformer is the high controllability, which can be achieved by utilizing the power electronic devices. Based on this, the analysis shows that the power electronic transformer (PET) and hybrid distribution transformer (HDT) are two alternative circuit schemes for the intelligent distribution transformer. The basic working principle of PET and HDT are introduced, and the several typical topologies of the intelligent distribution transformer based on PET, HDT and the extended HDT are presented and their characteristics are analyzed. Based on a specific application scenario in the distribution network, the working principle, reliability, economy, controllability of the intelligent distribution transformer based on PET and HDT are compared, and the variation trend of each performance is presented when the ratio of the conversion power increases. Finally, the future development trend of the intelligent distribution transformer are analyzed.