The High-Voltage Intelligent Power Module with Series-Connected Silicon Carbide MOSFETs

Silicon carbide (SiC) power devices offer superior performance over silicon couterparts, with higher switching frequencies/speeds and lower losses. The higher energy band enables SiC to achieve higher voltage rating, thus enables it to be appropriate for the high-voltage application scenarios. However, for the medium voltage(≥3.3 kV), the cost of a single chip will increase sharply compared with the main stream 1.2 kV SiC chips. To reduce the cost for the medium-voltage power module, this paper introduces a 3.3kV SiC intelligent power module (IPM) based on series 1.2 kV SiC MOSFETs. Considering that the voltage balancing between series MOSFETs is the most critical issue, the switching trajectory of the series-connected MOSFETs is comprehensively analyzed using piecewise behavior model. The steady-state voltage imbalance is minimized with passive method and the dynamic voltage imbalance is suppressed with adjustable integrated gate driver. The design process of the proposed IPM is introduced and the functionality is validated with LTspice simulation and experimental results.