Design and Experimental Analysis of a Modular Smart Transformer Architecture

The Smart Transformer (ST) technology has evolved significantly in the last years, but only few studies have discussed the system level design and explored the system with relevant experimental results. This paper presents the design and experimental analysis of a three-phase 100 kW Smart Transformer, with the aim to demonstrate the potential of such technology in terms of efficiency. The ST architecture explored in this work is composed of two-stage: AC-DC and DC-DC. The first is based on the Cascaded H-Bridge (CHB), and the second is based on the Quadruple-Active-Bridge (QAB) converter. The optimum design of each stage is carried out using the computer-aided approach, where an algorithm is used to select the optimum parameters and components. Moreover, the optimum number of modules in terms of cost and losses is determined. The ST architecture was built and tested in the laboratory. The system has shown an efficiency of approximately 94.6%, demonstrating the potential to be very efficient.