DC-arcing detection by noise measurement with magnetic sensing by TMR sensors

An arc fault establishes a current path in the air which may cause malfunction of direct current (dc) system and even a fire hazard. Arc fault detection is essential to improving the reliability, efficiency, and safety of the dc system. However, the randomness of dc arc faults makes it difficult to define their characteristics. In this paper, a magnetic-sensing-based technique is proposed to detect dc arc. This paper developed a promising dc-arcing detection technique based on the analysis of frequency-domain features of the magnetic field measured by a magnetic sensor. The effects of the supply voltage, load current, and electrode diameter on the frequency domain of the arc current were investigated. The experimental results show that the proposed detection technique could reliably discriminate the normal operation and arc fault. This technique is cost-effective because it can be implemented with low-cost magnetoresistive sensors and does not require an expensive current transformer.