A Framework for Inverter Aging Estimation and Failure Prognosis

This paper presents a framework to perform inverter failure prognosis in automotive applications. More specifically, this paper proposes a method to estimate the inverter aging and degradation status through monitoring health indicator performance. The health indicators proposed in this paper are based on the device collector to emitter voltage (Vce) for IGBTs or drain-to-source voltage (Vds) for MOSFETs and thermal resistance Rth to indicate electrical and thermal degradation, respectively. In addition, a rainflow counting method is used in this paper to estimate the inverter thermal degradation. Combined with the performance-based health indicators, it allows for more accurate prognostic decision-making. If the prognosis algorithm determines that the inverter has degraded to a certain level, it alerts the customers for scheduling maintenance ahead in order to prevent any further damage or unnecessary repairs.