Power based Fault Detection Method for PV Arrays

Faults occurring in solar PV systems could subsequently lead to safety hazards and negatively impact reliability and system efficiency. While many fault detection methods exist for fault identification and protection of solar PV systems, recent studies revealed several shortcomings under certain conditions such as partial shading, and low irradiance. This paper investigates faults in PV systems and conducts pattern analysis for changes in PV systems occurring during faults. Several quantities are considered such as changes in power, fault current, and voltage under both homogenous and partial shading conditions at a variety of fault resistances and fault locations. The observed patterns are then exploited to develop a simple approach for detecting faults in PV systems under homogeneous and partial shading conditions. The proposed approach can also differentiate between the occurrence of faults and partial shading. The effectiveness of the method to detect faults has been verified under various atmospheric and partial shading conditions through MATLAB/Simulink simulations.