This paper presents an augmented design method for the dc/dc modular multilevel converter considering the control (e.g., the phase difference between arms ac voltages) and hardware aspects (e.g., type and number of submodules (SMs)) of the converter simultaneously. The proposed augmented design determines the number of SMs and their types (e.g., half- or full-bridge) in each arm and phase difference between arms ac voltages that minimize the total converter losses. Computationally-efficient analytical and semi-analytical methods are proposed to estimate the conduction and switching losses. To verify the effectiveness of the proposed method, the losses obtained from the proposed analytical and semi-analytical methods are compared with the results of the detailed converter switching model implemented in the Simulink environment. The performance of the converter designed by the augmented approach is compared with the conventional topology in terms of total losses and the number of SMs. The comparative study showed that the proposed design method yields a converter with lower total losses and number of SMs. Moreover, the proposed design method extends the operation regime of the converter, especially when the dc links voltage levels are close; this extension is not possible in the conventional modular dc/dc converter.

中文翻译：

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DC/DC模块化多电平转换器的增强设计提高效率并减少SM数量

本文提出了一种 dc/dc 模块化多电平转换器的增强设计方法，同时考虑转换器的控制（例如，臂交流电压之间的相位差）和硬件方面（例如，子模块 (SM) 的类型和数量）。建议的增强设计决定了每个臂中 SM 的数量及其类型（例如，半桥或全桥）以及臂交流电压之间的相位差，以最大限度地减少总转换器损耗。提出了计算效率高的分析和半分析方法来估计传导和开关损耗。为了验证所提出方法的有效性，将从所提出的分析和半分析方法中获得的损耗与在 Simulink 环境中实施的详细转换器开关模型的结果进行比较。将增强方法设计的转换器的性能与传统拓扑在总损耗和 SM 数量方面进行比较。比较研究表明，所提出的设计方法产生的转换器具有更低的总损耗和 SM 数量。此外，所提出的设计方法扩展了转换器的运行范围，尤其是当直流链路电压水平接近时；这种扩展在传统的模块化 DC/DC 转换器中是不可能的。特别是当直流链路电压水平接近时；这种扩展在传统的模块化 DC/DC 转换器中是不可能的。特别是当直流链路电压水平接近时；这种扩展在传统的模块化 DC/DC 转换器中是不可能的。