Lifetime comparison of IGBT modules in Grid-connected Multilevel PV inverters Considering Mission Profile

The power semiconductor switches are the most unreliable devices in the Photovoltaic (PV) energy conversion system. Thermal stress is the prime cause behind the power semiconductor switch failure mechanism, the selection of switching strategy and converter topology can have a notable effect on the converter reliability. This paper presents a lifetime comparison of Insulated-Gate Bipolar Transistor (IGBT) modules in three classical multilevel inverter topologies on the basis of power cycling, thermal cycling, and lifetime performance. The electro-thermal analysis has been implemented to identify the amplitude of the temperature swings and mean junction temperature. The Bayer lifetime model is used to evaluate the consumed lifetime of IGBT modules in the multilevel inverters based on the calculation method of numerical junction temperature. The accuracy in lifetime estimation has improved by considering the mission profile. The study shows that the IGBT modules in cascaded H-bridge multilevel inverter have a higher lifetime when compared to the other two classical multilevel inverters.