Earlier conventional transformers usage in power grids has had a fairly one-sided existence for many decades. An interesting, challenging and promising solution for this is smart grids. Smart grids are more flexible ,intelligent enough to integrate a great amount of renewable energy and energy storage systems, which calls for more flexible and more controllable smart grids. Smart transformer (ST) with power electronics technology has found its application in the power distribution system which executes a significant working role in the forthcoming electrical distribution grid system; deliver many advanced grid services related to the traditional transformer. The solid state transformer advanced functionalities are capable enough to exploit the load dependence on voltage for providing services to the distribution and transmission grids. This paper aims at providing a broad view of comprehensive study of the current status of smart transformers around the world and applications to the researchers and the application engineers dealing with power quality issues.

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