EMI Propagation Path Modeling of 3-Level T-type NPC Power Module with Stacked DBC Enabled EMI Shielding

3-level T-type neutral point clamped (NPC) topology is more popular than its 2-level counterparts in energy conversion systems due to their higher efficiency, lower harmonics (THD), and reduced voltage stress on the switches. Wide bandgap (WBG) semiconductors have become the ultimate choice for future high-performance power electronics energy conversion due to their superior material properties compared to traditional silicon power devices. As a wide-bandgap device, while SiC's faster-switching speed improves overall efficiency by reducing switching loss, the faster voltage and current gradient (dv/dt and di/dt) generate electromagnetic interference (EMI) noise, requiring larger and complicated filter design. A stacked DBC (direct bonded copper) based T-type NPC power module has been proposed, designed, and tested where additional DBC will be acting as an EMI shield. The EMI noise propagation path has been modeled and compared to a traditional power module. A 21 dB reduction of CM (common mode) noise has been observed.