This paper aims to point out and demonstrate the opportunities enabled by wide-bandgap (WBG) devices for multilevel converters, contributing to the international technology roadmap for WBG power semiconductors (ITRW). The emergence of silicon carbide (SiC) and gallium nitride (GaN) devices offers new opportunities to push the boundaries of power converter performances. Featuring high single-device blocking voltage and ultra-low switching loss, WBG devices can enable a group of multilevel converters with simplified structures and a higher number of levels to be practically implemented in applications with various power levels. This paper highlights how the use of WBG devices can reduce the number of required devices in the simplified multilevel topologies, how the capacitor voltage balance can be achieved with the newly proposed redundant level modulation (RLM) enabled by the ultra-low switching loss of WBG devices and how the switching frequency and efficiency can be improved with WBG multilevel converters. A 1.2 kV/100 kW, three-phase demonstrator implemented with a simplified four-level active neutral point clamped (ANPC) structure and commercial SiC power modules is studied to show the opportunities brought by WBG devices for multilevel converters. A voltage balancing scheme based on the RLM and a power loss analysis are presented for this configuration.

中文翻译：

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具有简化结构和电容器电压平衡功能的宽带隙器件启用多电平转换器


本文旨在指出并展示宽带隙 (WBG) 器件为多电平转换器带来的机遇，为 WBG 功率半导体 (ITRW) 的国际技术路线图做出贡献。碳化硅 (SiC) 和氮化镓 (GaN) 器件的出现为突破功率转换器性能的界限提供了新的机会。 WBG器件具有高单器件阻断电压和超低开关损耗的特点，可以使一组结构简化、级数更多的多电平转换器在各种功率电平的应用中得到实际应用。本文重点介绍了如何使用 WBG 器件来减少简化的多电平拓扑中所需器件的数量，以及如何通过新提出的冗余电平调制 (RLM) 来实现电容器电压平衡，该冗余电平调制 (RLM) 是由 WBG 的超低开关损耗实现的器件以及如何使用 WBG 多电平转换器提高开关频率和效率。研究了采用简化的四电平有源中性点钳位 (ANPC) 结构和商用 SiC 功率模块实现的 1.2 kV/100 kW 三相演示器，以展示 WBG 器件为多电平转换器带来的机遇。针对该配置提出了基于 RLM 的电压平衡方案和功率损耗分析。