Comparative analysis of the reliability of grid-connected photovoltaic power systems

This study compares the reliability performance of string inverter structure and central inverter structure for grid-tied solar photovoltaic (PV) systems. The impact of input power variation and ambient-conditions on failure rates of PV system components are quantified and incorporated in the reliability analysis. Aging failure in PV panels is also modeled to evaluate the life cycle reliability of both types of PV systems. Sensitivity analyses are extensively conducted to explore the impact of different factors on the performances of different PV systems. Test results on a practical 20 kW PV project are presented to demonstrate the effectiveness of the presented method.