A Review of Multilevel Inverter Topologies in Electric Vehicles: Current Status and Future Trends

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.

牵引逆变器作为电动交通工具中的关键部件，在拓扑结构、调制和控制方案方面一直是许多研究项目的主题。最近，一些知名的电动汽车制造商使用了更高电压的电池，以受益于更低的电流、更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，一些多电平结构已被作为替代两电平逆变器的一种可行且高效的选择进行研究。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，这使其成为该应用中有吸引力的解决方案。本文对牵引逆变器中更高直流母线电压的优缺点进行了研究，并综述了近期针对电动交通工具应用的多电平逆变器拓扑结构的研究。在效率、成本、功率密度、电能质量、可靠性和容错能力方面对多电平逆变器及其两电平对应物进行了比较。此外，基于电动交通中最重要的标准对不同的多电平逆变器拓扑结构进行了全面比较。还讨论了未来的趋势和可能的研究领域。