This article presents a comprehensive design and validation of a compact all-silicon carbide (SiC) 250-kW T-type traction inverter with a power density of 25 kW/l and 98.5% peak efficiency. All the operation modes and switching transitions in a T-type phase leg are analyzed to model the semiconductor power losses over a fundamental cycle. Special attention has been paid to investigate the behavior and losses due to the reverse conduction of the SiC MOSFETs. Then a loss model is built based upon this analysis to calculate the device loss distribution and system efficiency, which is further used to determine the optimal switching frequency. In addition, detailed inverter system design and prototyping procedure, including the selection of SiC modules and dc-link capacitors, and the optimization of a fourlayer laminated busbar, are presented. In this article, the T-type phase leg is formed by a normal half-bridge module and a common-source module. The switching performance and losses in this configuration are different from two-level topology that only uses one SiC module. Therefore, the switching performance and the associated switching energy in each switch position are characterized using a custom clamped inductive load (CIL) test setup designed for a T-type phase leg. The performance of the full power traction inverter prototype has been verified experimentally using pulse testing and continuous power testing.

中文翻译：

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250 kW全碳化硅高密度三电平T型逆变器的设计与验证

本文介绍了功率密度为25 kW / l，峰值效率为98.5％的紧凑型全碳化硅（SiC）250 kW T型牵引逆变器的综合设计和验证。分析了T型相脚中的所有工作模式和开关转换，以对基本周期内的半导体功率损耗进行建模。已经特别注意研究由于SiC MOSFET的反向传导而引起的行为和损耗。然后，基于该分析建立损耗模型，以计算器件损耗分布和系统效率，并将其进一步用于确定最佳开关频率。此外，还介绍了详细的逆变器系统设计和原型制作过程，包括SiC模块和直流母线电容器的选择以及四层层压母线的优化。在本文中，T型相脚由普通的半桥模块和共源模块组成。此配置中的开关性能和损耗不同于仅使用一个SiC模块的两级拓扑。因此，使用为T型相脚设计的定制钳位电感负载（CIL）测试装置来表征每个开关位置的开关性能和相关的开关能量。全功率牵引逆变器原型的性能已通过脉冲测试和连续功率测试进行了实验验证。使用为T型相脚设计的定制钳位电感负载（CIL）测试装置来表征每个开关位置的开关性能和相关的开关能量。全功率牵引逆变器原型的性能已通过脉冲测试和连续功率测试进行了实验验证。使用为T型相脚设计的定制钳位电感负载（CIL）测试装置来表征每个开关位置的开关性能和相关的开关能量。全功率牵引逆变器原型的性能已通过脉冲测试和连续功率测试进行了实验验证。