Intelligent Transformer Unit Topology Using Additional Small Power Converter Based on Conventional Distribution Transformer

This paper proposes a new Intelligent Transformer Unit (ITU) topology. The proposed intelligent transformer unit can be constructed just adding a three-leg converter to the conventional distribution transformer. With the proposed topology, the magnitude of the distribution voltage can be kept constant and harmonics of the distribution voltage can be reduced. Also, transmission efficiency can be improved by improving power factor of the high voltage side of the distribution transformer. Furthermore, compared to the previous intelligent transformer unit based on full-power ratings of power semiconductors, the proposed topology is more efficient because most of the power is delivered through conventional distribution transformer. Simulations and experiments were performed and the result reveals the effectiveness of the proposed topology.