Investigation on Topology and Control for Smart Transformer-fed Active Distribution Network

Smart transformer (ST), which is a power electronics-based transformer with intelligent control capability to support and manage the fed power grids, can not only provide dc connectivity, but also power flow control capability. Active distribution network (ADN) is an advanced solution to host distributed generation and energy storage system. ST-fed ADN has the capability to decouple the upstream main grids and the fed power grids, avoiding faults and disturbances in the main grids impacting the ADN, and meanwhile providing the advanced support for the main grids. There are different topology and type of ST-fed ADN, resulting in different hardware cost and services provided to the modern power grids. Hence, this paper studies the topology and control strategy of the ST and its fed electricity grid to show the difference of ST on grid support and control.