Lifetime estimation for IGBT modules in power converter under power fluctuation condition

As a key component of high-power system, insulated gate bipolar transistor (IGBT) plays a critical role in safe and reliable operation of the converter system. Especially in renewable energy generation, power converter and its power semiconductors usually suffer from complicated thermal loadings due to large-scale fluctuations of processing power, which leads to lower reliability and shorter service life compared with traditional power equipment. Therefore, accurate lifetime estimation under power fluctuation condition is desired for reliability prediction and health management of power converter. However, the existing lifetime estimation methods for power converter are not yet suitable in power fluctuation condition, because the aging effects due to the amplitude of cyclic junction temperature variations ΔT _j are not well considered. Consequently, a relatively more advanced approach is proposed in this paper, which is based on the Physics-of-Failure (PoF) models and takes into account aging effects of various amplitudes of ΔT _j .