Condition monitoring and failure prognosis of IGBT inverters based on on-line characterization

An inverter characterization technique is used to improve inverter fault diagnosis and prognosis techniques with the demonstrative bond wire lift-off fault. Knowledge of the nonlinear voltage-current characteristic of each inverter device is used to achieve these improvements. Three contributions are made in this paper to the field of inverter condition monitoring by using the characterization technique: use of the inverter device characteristics to improve a classifier-based diagnostic technique, direct use of the device characteristics for diagnosis, and improving the calculation of remaining useful life with the device characteristics. The diagnostic method improvements are verified experimentally by adding resistances to create an artificial fault. Thermal and electrical simulations are used to demonstrate the improvements made to the prognostic method.