Traction inverter, as a critical component in electrified transportation, has been the subject of many research projects in terms of topologies, modulation, and control schemes. Recently, some of the well-known electric vehicle manufacturers have utilized higher-voltage batteries to benefit from lower current, higher power density, and faster charging times. With the ongoing trend toward higher DC-link voltage in electric vehicles, some multilevel structures have been investigated as a feasible and efficient option for replacing the two-level inverters. Higher efficiency, higher power density, better waveform quality, and inherent fault-tolerance are the foremost advantages of multilevel inverters which make them an attractive solution for this application. This paper presents an investigation of the advantages and disadvantages of higher DC-link voltage in traction inverters, as well as a review of the recent research on multilevel inverter topologies for electrified transportation applications. A comparison of multilevel inverters with their two-level counterpart is conducted in terms of efficiency, cost, power density, power quality, reliability, and fault tolerance. Additionally, a comprehensive comparison of different topologies of multilevel inverters is conducted based on the most important criteria in transportation electrification. Future trends and possible research areas are also discussed.

中文翻译：

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电动汽车多级逆变器拓扑的回顾：现状和未来趋势

牵引逆变器作为电气化运输的重要组成部分，已在拓扑，调制和控制方案方面成为许多研究项目的主题。近来，一些知名的电动汽车制造商已经利用较高电压的电池来受益于较低的电流，较高的功率密度和更快的充电时间。随着电动汽车中直流母线电压不断升高的趋势，已经研究了一些多级结构作为替代两级逆变器的可行而有效的选择。更高的效率，更高的功率密度，更好的波形质量以及固有的容错能力是多电平逆变器的首要优势，这使其成为该应用的有吸引力的解决方案。本文对牵引式逆变器中较高的直流母线电压的优缺点进行了研究，并对电动化运输应用中多电平逆变器拓扑的最新研究进行了回顾。在效率，成本，功率密度，功率质量，可靠性和容错能力方面，对多级逆变器与两级逆变器进行了比较。此外，基于运输电气化中最重要的标准，对多电平逆变器的不同拓扑进行了全面比较。还讨论了未来的趋势和可能的研究领域。在效率，成本，功率密度，功率质量，可靠性和容错能力方面，对多级逆变器与两级逆变器进行了比较。此外，基于运输电气化中最重要的标准，对多电平逆变器的不同拓扑进行了全面比较。还讨论了未来的趋势和可能的研究领域。在效率，成本，功率密度，功率质量，可靠性和容错能力方面，对多级逆变器与两级逆变器进行了比较。此外，基于运输电气化中最重要的标准，对多电平逆变器的不同拓扑进行了全面比较。还讨论了未来的趋势和可能的研究领域。