PV array fault DiagnosticTechnique for BIPV systems

To ensure the cost effectiveness of photovoltaic power plants (PVPPs) it is needed to keep the levelof yearly energy production as high as possible. In this context, efficiency and availability of a PVPPhave to be checked continuously. The section of a PVPP which deserves more attention is surely the PVarray, where many fault conditions can happen (shading, by-pass diode faults, cable interruptions, andso on). A diagnostic tool to detect faults in the PV array is desirable, even if its implementation is criticalowing to: the fluctuation of the operating conditions (mainly irradiance), which complicates the instan-taneous response investigation and costs and implementation constraints to implement a distributed (atPV module level) or semi-distributed (at string level) monitoring/diagnostic system. Particularly, for BIPVsystems, further constraints related to the regular access for inspection and maintenance operations haveto be considered. In this paper, the procedure adopted to develop and validate a diagnostic tool can besummarized in four steps: (1) using real data to model the PV array; (2) introducing several fault scenar-ios on the real PV string and analyzing the relative modifications of the I–V curves; (3) assessment of themeaningful parameters useful to discern the different faults by means of a PV generator (PVG) simulatorbased on a metaheuristic technique denominated ABC-DE; (4) proposition of several fault signing tablesto assess the PV plant fault diagnostic