Design of a Highly Efficient (97.7%) and Very Compact (2.2 kW/dm $^3$) Isolated AC–DC Telecom Power Supply Module Based on the Multicell ISOP Converter Approach

Abstract

The rising electricity demand of data centers has initiated a development trend toward highly efficient power supplies. Therefore, a multicell converter approach for a telecom rectifier module breaking through the efficiency and power density barriers of traditional single-cell converter systems is presented in this paper. The potential of the multicell approach for high efficiency is derived from fundamental scaling laws of different system performance aspects in dependence of the number of converter cells and the benefits of the interleaving technique. Based on the available degrees of freedom in the design of such a converter system, a comprehensive multiobjective optimization of the entire system with respect to efficiency and power density is performed with detailed component loss and volume models. In order to verify the analytical models and the design procedure, a hardware demonstrator of a 3.3 kW multicell 230 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AC</sub> /48 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DC</sub> telecom power supply with N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cells</sub> = 6 isolated converter cells in an input-series output-parallel arrangement is presented with measurement results indicating a maximum efficiency of η = 97.7% and a power density of p = 2.2 kW/dm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> (= 36 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ). Furthermore, different paths for future performance improvements of the multicell arrangement are outlined.