A Dual function of Buck-Boost Converter in Photovoltaic System: MPP Tracker and I-V Tracer for Fault Diagnosis Applications

This paper proposes a Current-Voltage (I-V) curve tracer for photovoltaic string characterization and fault detection. The proposed tracer is based on a Buck-Boost converter working under two operation modes. The first is the usual maximum power tracking mode, to deliver maximum power to the load. The second is an I-V curve tracer, able to extract the PV characteristic in case of fault occurrence. The fault is then classified using the extracted curves by a fault diagnosis program. The simulation results have proven that the system operates with a good accuracy in both operations. Furthermore, the diagnosis algorithm is able to detect and distinguish five of the common fault types.