In situ diagnostics and prognostics of solder fatigue in IGBT modules for electric vehicle drives

Bing Ji, Xueguan Song, Wenping Cao, Volker Pickert, Yihua Hu, John William Mackersie, Gareth Pierce

Research output: Contribution to journalArticlepeer-review


This paper proposes an in situ diagnostic and prognostic (D&P) technology to monitor the health condition of insulated gate bipolar transistors (IGBTs) used in EVs with a focus on the IGBTs' solder layer fatigue. IGBTs' thermal impedance and the junction temperature can be used as health indicators for through-life condition monitoring (CM) where the terminal characteristics are measured and the devices' internal temperature-sensitive parameters are employed as temperature sensors to estimate the junction temperature. An auxiliary power supply unit, which can be converted from the battery's 12-V dc supply, provides power to the in situ test circuits and CM data can be stored in the on-board data-logger for further offline analysis. The proposed method is experimentally validated on the developed test circuitry and also compared with finite-element thermoelectrical simulation. The test results from thermal cycling are also compared with acoustic microscope and thermal images. The developed circuitry is proved to be effective to detect solder fatigue while each IGBT in the converter can be examined sequentially during red-light stopping or services. The D&P circuitry can utilize existing on-board hardware and be embedded in the IGBT's gate drive unit.
Original languageEnglish
Pages (from-to)1535-1543
Number of pages9
JournalIEEE Transactions on Power Electronics
Issue number3
Early online date23 Apr 2014
Publication statusPublished - Mar 2015

Bibliographical note

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  • electric vehicles
  • fault diagnosis
  • insulated gate bipolar transistors
  • prognostics and health managemet
  • reliability
  • thermal variable measurement


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