Design and Evaluation of a 1200-V/200-A SiC Three-Level NPC Power Module

The silicon carbide (SiC) power module is one of the most popular semiconductor devices in industrial applications with the enhanced current rating. In this paper, a 1200-V/200-A SiC three-level (3L) module with neutral point clamped (NPC) topology is designed and validated. Compared with other existing works, the drain current of the designed module is accurately measured by a custom-made current transformer (CT) combined with a commercially off-the-shelf current probe (CP), which is critical for power loss evaluation. Based on the simulation and experiment results, it can be found that the maximum internal commutation loop stray inductance is no more than 40 nH, and the total switching loss can be reduced more than 30
${\%}$
compared with the hybrid 3L NPC module (Si IGBTs+SiC SBDs). Meanwhile, the power loss evaluation demonstrates that the designed 3L NPC module with all-SiC device is more suitable for high-voltage and high-frequency applications compared with its 2L counterpart, and the thermal simulation shows that the maximum junction temperature is less than 120
$^{\circ }$
C when the module operates as a buck converter with
$V_{DC}$
= 600 V,
$I_{o}$
= 150 A, and
$f_{s}$
= 100 kHz. In addition, compared with the 2L module, the 3L one presents enhanced spectrum amplitude in the high frequency (HF) range (
$\ge$
10 MHz) for the high-voltage applications, which indicates higher electromagnetic interference (EMI) noise. Then, two types of snubber circuits are used to suppress the HF oscillation of the SiC 3L NPC module and alleviate the EMI noise as well according to the experiment results.