Asymmetrical Press-Pack IGBT for Modular Multilevel Converter

In modular multilevel converter (MMC) systems, it’s important to improve the effectiveness and dependability of power semiconductor devices. In order to improve the chip utilization and lower the peak junction temperature, based on the practical upper and lower bridge arms current, the asymmetrical press-pack IGBT devices were proposed. In this paper, the current of the upper and lower bridge arms of the sub-module is obtained through simulation, and the actual power losses of the IGBT and anti-parallel FRDs under practical operation are calculated. Then the power losses are imported into the finite element simulation, and the peak junction temperature and temperature distribution of proposed asymmetrical press-pack IGBT modules were analyzed. The results show that the proposed asymmetrical press-pack IGBT structure not only improve the chip utilization, but also lower the peak junction temperature. This contributes to the reliability of the MMC system.