RUL Estimation for Power Electronic Devices Based on LESIT Equation

The LESIT equation is a well-known model to estimate the lifetime of power electronic devices. However, the equation is a static lifetime model that can estimate the total lifetime but not the dynamic lifetime over time and the Remaining Useful Lifetime (RUL), because the equation is not related to time or cycle count. In the paper, we first introduce the concept of dynamic lifetime, i.e., lifetime over time, and include time into the equation to allow it to calculate dynamic lifetime, and then propose a simple equation to conduct the RUL estimation assuming linear damage accumulation. In our experiments using aggregated aging tests, we show that the proposed RUL estimation method can fully capture the general linear decreasing trend of RUL, and in most cases, it gives very accurate estimates, where the deviation depends on the accuracy of the original LESIT estimation.