Thermal-Electrical Fusion for Real-Time Condition Monitoring of IGBT Modules in Transportation Systems

Area of Science:

• Electrical Engineering
• Materials Science
• Reliability Engineering

Background:

• Insulated Gate Bipolar Transistors (IGBTs) are crucial for power electronics in transportation.
• Solder layer and bond wire failures under thermal stress degrade IGBT reliability.
• Current monitoring methods often require invasive sensors or are insufficient for detecting these specific failures.

Purpose of the Study:

• To develop a novel, non-invasive health monitoring framework for IGBT modules.
• To enable simultaneous diagnosis of solder layer fatigue and bond wire aging.
• To enhance the operational safety and predictive maintenance of transportation electrification systems.

Main Methods:

• Synergistic integration of micro-scale spatial thermal analysis and microsecond electrical dynamics inversion.
• Non-invasive baseplate temperature measurements correlated with thermal impedance for solder assessment.
• Cost-effective inversion algorithm to estimate on-state voltage (Vce,on) for bond wire aging diagnosis, utilizing Foster-model-based junction temperature (TJ) estimation.
• Fusion of health states from both failure modes for comprehensive condition evaluation.

Main Results:

• Accurate, non-invasive assessment of solder layer fatigue using normalized thermal gradient (∇TP) and thermal impedance (ZJC).
• Effective estimation of bond wire aging by calculating power loss and isolating conduction loss (Pcond) to determine Vce,on at a unique current inflection point (IC,inf).
• Experimental validation confirming the framework's accuracy in tracking both degradation modes simultaneously.

Conclusions:

• The proposed framework offers a practical and economical solution for online IGBT condition monitoring.
• It enhances predictive maintenance and operational safety in demanding transportation applications.
• The method effectively addresses critical failure modes in IGBT modules without requiring specialized sensors.