The detection of DC arc fault: Experimental study and fault recognition

DC arc fault introduces major safety concerns in a wide variety of power electronic applications. However, the randomness and instability of dc arc makes it difficult to be detected. In this paper, an experimental system to study the characteristics of series dc arc is designed and different tests were conducted in order to determine the influence of different factors to the arc such as gap length, current, etc. During the experiments, the load current was varied from 6 A to 30 A, and dc source voltage was changed from 75 V to 300 V. Also, dc arc test with fixed power supply voltage and load current but changing gap length were conducted to examine the influence of arc length. Based on the experimental results, a primary V-I characteristics study was carried out. Current variation analysis was performed to investigate the pulse patterns of the arc current for detection purposes. High frequency arc impedance under different test conditions was also investigated. Lastly, time frequency analysis was applied to the different arc current signals in order to examine the impacts of factors such as load current, dc bus input voltage to the arc current with respect to frequency domain. The results of this paper provide insights of the dc arc characteristics as well as methods for dc arc fault detection.