Identification technique of DC series arc-fault strings in photovoltaic systems

The DC series arc-faults lead a risk due to an aging of photovoltaic system components enhanced by environmental factors and high DC voltages in already existing photovoltaic systems. Until recently, many research activities have focused on the detection of DC series arc-faults by current signature analysis. However, DC arc detector has two problems. Firstly, it is difficult to distinguish arc noise and switching noise of power conditioner by circuit current in photovoltaic system. Secondly, when a DC series arc fault occurs in the photovoltaic system, DC series arc-fault string cannot be specified because the arc noise is propagated in the circuit. In this paper, we propose two novel techniques for the DC series arc-fault detection and identification of faulty strings. Experiments were performed by generating DC series arc in the field. The proposed technique is investigated based on the experimental results in the terms of effectivity and applicability. © 2019 The Institute of Electrical Engineers of Japan.