Detection and Identification Technique for Series and Parallel DC Arc Faults

This paper proposes a series and parallel DC arc detecting and identifying (SPADI) technique using the frequency features of the load current (I-L) and the load voltage (V-L). The frequency changes in V-L and I-L under the series and parallel arc are different. The parallel arc can only raise the high-frequency components of V-L. In contrast, the high-frequency components of I-L can be increased in both series and parallel arcs. However, the increasing frequency range is different. The high-frequency components of I-L generated by the series arc are concentrated in the 5 kHz to 40 kHz band. Meanwhile, the high-frequency components of I-L caused by the parallel arc are observed evenly in all frequency ranges. Inspired by these features, V-L's 5 kHz to 100 kHz components are used to sense the parallel arc in the proposed technique. In addition, the series arc is detected using the 5 kHz to 40 kHz and 50 kHz to 100 kHz bands of I-L. Experimental tests verified the proposed algorithm implemented at the digital signal processor (DSP). As a result of 160 repeated tests, the probabilities of detecting the series and parallel arc were 100 % and 96.25 %, respectively. Moreover, the probability of correctly identifying the arc type when detecting the arc was 100 %. Also, the average detection times of the series and parallel arc were 0.11 s and 0.16 s, respectively.