Reliability and Lifetime Assessment of PV Inverter with Monte Carlo Approach

Grid-connected Photovoltaic System (GPVS) are proliferating at a high rate owing to their support in attaining sustainable energy goals, and efficient electrical power delivery. However, investigations reveal that the power electronic converters in GPVS are at risk of wear-out failures, which may lead to detrimental influence on the reliability of the whole system. Excessive stress in bond wire, chip solder, and substrate solder joint is a predominant cause of failure in insulated-gate bipolar transistor (IGBT) modules owing to cyclic stresses. Further, modeling these stresses, and accurate lifetime prediction in real-world operations remains challenging. This paper introduces a Monte Carlo-based analysis method for predicting lifetime in IGBT modules within a GPVS inverter. The approach accounts for variations in lifetime models, IGBT parameters, operational and environmental stresses. Solar PV mission profile variation having solar-irradiation, and temperature, is considered for a year. Monte-Carlo technique consider the variation in these factors, which further helps in precise lifetime evaluation, and consequently, reliability assessment in GPVS.