Reliability Assessment of Single-Phase PV Inverters

This paper investigates the reliability of two types of single-phase Photo-Voltaic (PV)inverters, which are a quasi-Z-Source Inverter (qZSI)and a conventional two-stage boost-based inverter. The converters reliability is estimated by employing a mission-profile based reliability assessment approach modeling the wear-out failure of fragile components, i.e., capacitors and semiconductor devices. The obtained results reveal that the conventional two-stage inverter has better reliability compared to the qZSI due to the higher voltage and current stresses on qZSI components. Furthermore, the impact of PV array configuration on the Shoot Through (ST)state of the qZSI and consequently on its reliability is illustrated. The analysis shows that a suitable PV array configuration can improve the qZSI reliability.