Photovoltaic Array Fault Detection Algorithm Based on Least Significant Difference Test

One major concern in solar systems is the health of the solar installation, specifically related to the undetected faults in the photovoltaic array. Any fault in the array could provoke power losses in the system and may generate security risks for the operative and technical personnel. The present paper proposes a novel fault detection and location algorithm in PV arrays. The algorithm is validated using numerical simulations of a PV array with the following faults: diode short circuit, open circuit, degradation of the parasitic serial resistance, and partial shadows. The proposed fault detection algorithm is based on the idea that a set of quasi-identical PV modules produces statistical equivalent results when faced with the same stimulus such as irradiance and temperature. All the modules should be connected at the same maximum power point tracker (MPPT). If there is one element affected by one fault its measurements will be different from the unaffected modules. The authors present a pseudo-code for this idea and tested in Simulink^®. The obtained results show the proposed algorithm can detect and locate faults occurring in the solar array with a delay of 3 samples.