Fault Ratio Enriched Anomaly Detection and Discrimination in a PV System Using a Fault Detector-Array Combiner Box

Photovoltaic (PV) power generation is susceptible to various permanent electrical faults, including line-to-line (LL), line-to-ground (LG), and open-circuit (OC) faults. Additionally, non-catastrophic, temporary shading faults can also occur. These faults can lead to changes in the I-V characteristics and cause a shift in the maximum power point (MPP). Permanent faults such as LL/LG and OC can significantly alter the array's open circuit voltage and short circuit current. This research proposes a novel sensor-less approach for detecting, discriminating, and locating different faults in a PV array. The proposed approach utilizes the mandatory Maximum Power Point Tracking (MPPT) reference to assess the likelihood of fault occurrence. It then analyzes the altered I-V characteristics to discriminate and locate the fault location within the PV array. To facilitate fault detection and categorization, a new Fault Detector-Array Combiner Box (FD-ACB) with power electronic switches has been developed. The effectiveness of the proposed algorithm is evaluated using a test setup consisting of three 4×4 sub-arrays. Detailed case studies involving LL/LG, OC, and shade faults are presented. The results demonstrate that the sensor-less FD-ACB setup has the potential to find (i) undetected and undiagnosed LL/LG and OC faults, (ii) discriminate shade and permanent faults, and (iii) locate the faulty PV sub-array vulnerable to permanent faults.