Grid-Tied PV Inverter Reliability Estimation Based on Mission Profile

With the increase in the energy demand, the grid-tied PV systems have become extensively popular. Though they are assumed to be highly reliable. However, in practical scenarios, like any complex system, they are prone to failures. Investigations have revealed that inverters are weakest components in terms of reliability in a grid-tied PV system. The key factor behind inverter to be the weakest link is that it has majority of power switching devices. These switching devices are susceptible to faults owing to various aspects. Furthermore, the next vulnerable component is a capacitor. These two components working and functionality highly affects the system reliability. The PV mission profile is another important factor in influencing the system reliability. Consequently, it is utmost important to study the reliability guidelines in such systems. This work provides a guidance towards estimating the overall lifetime and based on that, ultimately, predicting the reliability of a grid-tied PV system.