Power IT Lab
Power Electronic Links
Novel Packaging to Reduce Stray Inductance in Power Electronics
Shengnan Li (UT)
Leon M. Tolbert (UT/ORNL)
Fred Wang (UT/ORNL)
Madhu Chinthavali (ORNL)
Large stray inductance in conventional packaging for high current rated IGBT packages.
In inverter configuration, the conventional IGBT-Diode anti-parallel module induces
stray inductance. Stray inductance can cause overvoltage in inverters and dc-dc
converters when current changes, which increases EMI, and affects performance
of the converter.
Series combination of switch and diode forms basic switching cells: N-cell
and P-cell, which can be used to construct all commonly used DC-DC and
DC-AC converters. Each switching cell is dedicated to one load current direction.
Use p-cell and n-cell concept to change packaging technique. IGBT and diode
are packaged in a series arrangement instead of anti-parallel. For inverter
application, vertical layout of N-cell and P-cell could be exploited for
The rearrangement of the power module can reduce the stress on IGBTs of the
inverter. Therefore IGBT can work at higher power rating and/or have better
reliability and longer lifetime. It can also reduce the dead time requirement
needed when switching devices in an inverter leg. This also increases the
reliability of the inverter, makes it more difficult for a dc link short to
damage the inverter.
1. L. M. Tolbert, F. Z. Peng, F. H. Khan, S. Li, "Switching cells and their implications for power electronic
circuits," IEEE Power Electronics and Motion Control Conference, 2009, pp. 773-779.
2. S. Li, L. M. Tolbert, F. Wang, F. Z. Peng, "Reduction of stray inductance in power electronic
modules using basic switching cells," IEEE Energy Conversion Congress & Exposition, Atlanta,
Georgia, USA, Sept. 2010.