Thermal Analysis and Lifetime Estimation of Solar Inverters

Abstract

In modern energy sector the rise in renewable energy demand highlights the necessity of solar energy systems being operated with efficiency and reliability. In photovoltaic (PV) systems, solar inverters play important role on the system performance due to their high efficiency (>98%). However, reliability and lifetime of inverters are affected by PV operation conditions which can be named by mission profile. Thermal stress and total losses are the function of the field conditions which, reduce both the lifetime and the reliability of the semiconductors. In this study, thermal analysis are conducted using junction temperature data collected from inverters operated in various provinces and altitudes in Türkiye and lifetime estimation was performed based on rainflow counting, the Coffin-Manson model and Miner’s rule. The study results demonstrate that the wear rate of semiconductors rises due to temperature fluctuations and that accurate lifetime estimation is significant for decreasing our nation’s dependence on energy devices.