This study deals with (efficiency-power density) pareto optimisation of medium frequency transformers (MFTs) with considerations of voltage and frequency ( Vf ) constraints of semiconductors for mega-watt range input-series output-parallel (ISOP) connected dual-active bridges (DABs). A simple design methodology to include the Litz wire configuration in the optimisation process is proposed. Based on the presented design methodology, the effects of the semiconductors blocking voltage and switching frequency on the -pareto optimisation are evaluated. First, an idealised optimisation is carried out to understand the general behaviour of the optimum point. Second, brute-force optimisation is utilised to find the practical optimum solution based on the market availability of MFT components. Designing MFTs for a 1 MW 10 kV/600 V ISOP-DAB converter is the subject of numerical studies. The best trade-off between is selected as the final optimal solution and its design correctness is validated using three-dimensional finite-element analysis. Experimental tests on a 3 kW downscaled MFT prototype show that the proposed method is valid in practice.

中文翻译：

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Vf约束的 ηρ-ISOP-DAB转换器中频变压器的最优优化

这项研究涉及 （效率-功率密度）中频变压器（MFT）的最佳化，同时考虑电压和频率（ Vf ）兆瓦级输入串联输出并联（ISOP）连接的双有源桥（DAB）的半导体约束。提出了一种在优化过程中包括Litz导线配置的简单设计方法。基于提出的设计方法，半导体阻断电压和开关频率对半导体的影响。 -pareto优化进行评估。首先，进行理想化的优化以了解最佳点的一般行为。其次，基于MFT组件的市场可用性，利用蛮力优化来找到实用的最佳解决方案。数值研究的主题是为1 MW 10 kV / 600 V ISOP-DAB转换器设计MFT。两者之间的最佳权衡选择最终的最佳解决方案，并使用三维有限元分析验证其设计正确性。在3 kW缩小规模的MFT原型上进行的实验测试表明，该方法在实践中是有效的。