10kV SiC-based bidirectional soft-switching single-phase AC/DC converter concept for medium-voltage Solid-State Transformers
10kV SiC-based bidirectional soft-switching single-phase AC/DC converter concept for medium-voltage Solid-State Transformers
复制标题
适用于中压固态变压器的 10kV SiC 双向软开关单相 AC/DC 转换器概念
DOI：
10.3929/ethz-b-000130829
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
J. Kolar
中科院分区：
文献类型：
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作者：
D. Rothmund;D. Bortis;J. Huber;D. Biadene;J. Kolar
现有技术的PWM AC/DC转换器通常由于硬开关而遭受高开关损耗，并且因此在其效率和功率密度方面受到限制。在本文中，集成的三角电流模式（iTCM）操作的概念，使软开关在整个交流电源周期，可以克服PWM的限制，从而在一个更高的系统性能。因此，LC电路被添加到公知的基于全桥的PWM AC/DC转换器，其在内部将高三角电流叠加到AC市电电流，以便在每个开关周期中反转半导体中的电流方向，并且由此实现所有器件的软开关操作。在本文中，iTCM概念的详细介绍，其性能进行了比较，标准的PWM和TCM的方法。此外，所提出的iTCM概念被应用到10 kV的SiC-MOSFET为基础的双向25千瓦单相AC/DC转换器从6：6 kV中压交流电网运行。在这种情况下，与PWM相比，iTCM概念可以将开关频率提高近五倍，同时将总半导体损耗降低40%以上。
State-of-the-art PWM AC/DC converters often suffer from high switching losses due to hard-switching and thus are limited in their efficiency and power density. In this paper, the concept of the integrated Triangular Current Mode (iTCM) operation is introduced, which enables soft-switching over the entire AC mains period and can overcome the limitation of PWM, resulting in a higher system performance. Thereby, an LC-circuit is added to the well-known full-bridge-based PWM AC/DC converter, which internally superimposes a high triangular current to the AC mains current in order to reverse the current direction in the semiconductors in each switching cycle and by this enabling soft-switching operation of all devices. In this paper, the iTCM concept is presented in detail and its performance is compared to the standard PWM and TCM approaches. Furthermore, the proposed iTCM concept is applied to a 10 kV SiC-MOSFET-based bidirectional 25kW single-phase AC/DC converter operated from the 6:6 kV medium-voltage AC grid. In this case, compared to PWM, the iTCM concept allows to increase the switching frequency by almost a factor of five while the total semiconductor losses are reduced by more than 40%.