UT Power Engineering Laboratory - "Powering the Future"

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 further integration.

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.

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Min H. Kao Engineering Building