Comparative Analysis of Reliability for String and Central Inverter PV Systems in Accordance with the FMECA

The paper presents a comparative analysis of string and central inverter concept photovoltaic (PV) power systems reliability using failure mode, effects and criticality analysis (FMECA). Considering the previous experience in long-term operation and maintenance activities in two PV power plants (536 kWp and 2 MW) a short introduction to fault classification and a root-cause analysis oriented towards reliability improvement is presented. The FMECA was applied to the most common faults within the two plants and a comparative analysis of the system concept influence on system reliability is presented.