Abstract
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.
Highlights
I NSULATED gate bipolar transistor (IGBT) power modules have been widely used in high-voltage and high-power applications such as electric vehicles (EVs) [1], [2], ships [3], aircraft [4], wind turbines [5], smart grids [6], and industrial drives [7], primarily due to their superior performance in terms of power density, switching frequency, energy efficiency, and cost effectiveness
This paper develops a new in situ diagnostic and prognostic (D&P) method to estimate the changes in thermal impedance consequent upon occurred faults or thermal aging
Another tendency in IGBT packaging is to develop baseplate-free power modules which can eliminate the need for baseplates
Summary
I NSULATED gate bipolar transistor (IGBT) power modules have been widely used in high-voltage and high-power applications such as electric vehicles (EVs) [1], [2], ships [3], aircraft [4], wind turbines [5], smart grids [6], and industrial drives [7], primarily due to their superior performance in terms of power density, switching frequency, energy efficiency, and cost effectiveness. The capital and maintenance costs of power converters can be very high [9] and predominately affect the market acceptance of EVs. Over the last 20 years, this issue has been addressed by improving the device design at component levels (i.e., semiconductor design and packaging) and system levels (i.e., overengineering design, soft-switching, snubber circuit, advanced cooling and modulation schemes). Traditional reliability prediction methods such as MIL-HDBK-217 [21], PRISM [22], and Telcordia [23] are based on statistical and empirical data They employ the failure rate as a reliability index and generate a so-called bathtub curve (e.g., Fig. 1). Wear-out failures occur toward the end of the device lifetime, caused by the operational loading and environmental stresses During this period, the failure rate increases rapidly and effective. IGBT bondwire faults are extensively studied in a companion article [1] whereas this paper is devoted to the solder fatigue
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
