Current-Based Protection Scheme for Faults Within Utility-Scale Photovoltaic Arrays

Abstract

Undetected faults within photovoltaic (PV) arrays can result in permanent power loss and major catastrophic failures. This paper proposes a current-based protection scheme that detects and classifies string-to-ground and string-to-string faults in utility-scale PV arrays. The protection scheme operates based on string current waveforms comparison. Some salient features of this method include its capability to distinguish between fault and partial shading conditions, and its independence from meteorological data. The performance of the proposed approach is assessed on a utility-scale PV array under various conditions. The results verify the scheme's selectivity, sensitivity, high speed, and scalability.