Identification of Faults in PV Array using Maximal Overlap Discrete Wavelet Transform

The active Maximum Power Point Tracking (MPPT), presence of blocking diodes, low insolation and the similarity in I-V characteristics among certain Line-Line (LL) faults and partial shading conditions imply the detection of fault as a major task. The undetected faults in Photovoltaic (PV) array lead to power loss, reduced reliability, fast degradation and may even cause fire risks. This paper proposes an effective Fault Detection Algorithm (FDA) using Maximal Overlap Discrete Wavelet Transform (MODWT) that would identify and discriminate the faults from partial shading and uniform irradiation changing conditions. The FDA uses input data as PV array voltage, current, irradiation and temperature. Various LL faults under discrete environmental conditions are verified using MATLAB/Simulink and is laboratory tests on a 4×4 PV array using LABVIEW software.