Modeling and Feature Analysis of Photovoltaic DC Series Arc Faults

Abstract When a series arc fault occurs in photovoltaic DC system, the existing research mainly focuses on arc fault current waveform analysis and signal processing, failing to reveal the essential reason of current features change caused by the arc fault. To address this issue, this paper conducts research on the modeling and feature analysis of photovoltaic DC series arc faults. Firstly, based on existing research of photovoltaic cells, an equivalent circuit of the photovoltaic system is established. Secondly, the arc is divided into arc initiation stage and arc burning stage. Based on the dynamic characteristics of plasma, the physical impedance model of arc fault is constructed in stages, and the DC series arc fault equivalent circuit of photovoltaic system is established. Then, the current features of the monitoring point are analyzed from the two stages of arc initiation and arc burning, which provides a theoretical basis for defining the arc fault current features. Finally, a real experimental platform is built, and the features of arc fault current are analyzed and verified by real experimental data, and the influence of different factors on the features is discussed. The conclusion is beneficial to the subsequent arc fault feature extraction and provides a new perspective for arc fault detection, which has important practical engineering significance.