A Novel Series Arc Fault Detection Method using Sparks in DC Microgrids with Buck Converter Interface

With the increasingly prevalent application of dc systems, protection of such systems has become an important research focus. Given that many dc systems are augmented with buck converter interfaces, this paper proposes a novel method of series fault detection. Instead of exploiting the signatures of an arc, the proposed method detects a fault by sensing the intermittent discharges at the beginning of the fault which are caused by the high input capacitance of the interface. In this paper, the characteristics of such phenomena are investigated and a detection algorithm utilizing spark signatures, as well as crosscorrelation, is proposed. Experimental validation is designed and conducted on a scaled down dc microgrid with a constant power load (CPL) and the detection is achieved with Arduino Uno and Udoo X86. The results show that the proposed method detects sparks in a timely and accurate manner.