A computer‐aided design tool dedicated to isolated DC‐DC converters based on multiobjective optimization using genetic algorithms

Abstract

Purpose -This paper presents a computer-aided design (CAD) tool for the design of isolated dc-dc converters. Design/methodology/approach -This tool, developed in Matlab environment, is based on multiobjective optimization (MO) using genetic algorithms. The Elitist Nondominated Sorting Genetic Algorithm is used to perform search and optimization whereas analytical models are used to model the power converters. The design problem requires minimizing the weight, losses and cost of the converter while ensuring the satisfaction of a number of constraints. The optimization variables are, as for them, the operating frequency, the current density, the maximum flux density, the transformer dimensions, the wire diameter, the core material, the conductor material, the converter topology (among Flyback, Forward, Push-Pull, half-bridge and full-bridge topologies), the number of semiconductor devices associated in parallel, the number of cells associated in series or parallel as well as the kinds of input and output connections (serial or parallel) of these cells. Finally, the design of an auxiliary railway power supply is presented and discussed. Findings -The results show that such tool to design dc-dc power converters presents several advantages. In particular, it proposes to the designer a set of solutions -instead of a single one -so that he can choose a posteriori which solution best fits the application under consideration. Moreover, interesting solutions not considered a priori can be found with this tool. Originality/value -To the best of the authors' knowledge, such a CAD tool including a MO procedure taking several topologies into account has not been suggested so far.

Evaluation of power loss and mass gains of SiC versus Si-based switch-mode power supplies using a multiobjective optimization CAD tool

“…As above said, the overall mass of the converter is mainly dominated by that the passive components and, more particularly, the mass of the MF transformer. Hence, from the well-known area product [18] (which is employed here to design the transformer), the following relation holds: (2) which is more or less in line with the shape of the SiC-based evolution represented in Fig. 6 Finally, the loss breakdown (conduction and switching) related to the transistors of one dc-dc cell is shown in Fig.…”

“…The existing CAD tool, previously published by the authors [2] and that was initially conceived for high power dcdc converters, is briefly reviewed in this section. This tool is founded on a multiobjective optimization using GA.…”

“…Indeed, it involves the minimization of multiple conflicting objectives as, e.g., power losses and mass, while ensuring the satisfaction of several technological and thermal constraints. In this context, the authors proposed in a previous work [2] a computer-aided design (CAD) tool dedicated to isolated dc-dc converters, based on multiobjective (MO) optimization using genetic algorithms (GA). A key advantage of that tool is that it does not restrict to one solution.…”

“…Instead, it proposes to the designer a set of optimal solutions so that he can choose a posteriori which solution best fits the application under consideration or which objective function to favour. For instance, in [2], [3], the design of the medium-frequency (MF) conversion stage of a 100 kW auxiliary railway SMPS has been addressed considering conventional Si power devices. More recently, in order to highlight its flexibility, the tool has been adapted to take into account the specific requirements of a SMPS for space application at a much lower power level (a few tens of watts) [4].…”

Comparison of the influence of Si and SiC semiconductor devices on power loss and weight of multiobjective optimal designed power converters

“…The next natural step should consists in a quantified analysis concerning the whole converter design, with an emphasis on the gain in terms of losses and weight compared to Si-based converters. To the best of the author knowledge, such a study has not been proposed yet.In this work, we use our MO design tool [24,25], based on GA, to compare the power loss and weight of an isolated DC-DC converter used for railway applications, and composed either of Si or SiC power devices. Indeed, among SiC, GaN and diamond, the SiC material appears as the most mature technology, as described below.…”