Author(s)

Jing Zhang, Kai Hu, Xinyu Zhao and Chuanxian Luo

Corresponding Author

Jing Zhang

ABSTRACT

The state detection of DC cable need the support of advanced sensing technology. Leakage current is an important means to characterize the insulation state of cables. Aiming at the demands of current measurement of XLPE insulated cable, a leakage current sensor based on giant magnetoresistance effect was developed, and an experimental platform for leakage current detection of XLPE cable was built. Taking the defect of XLPE insulated scratch as the research object, the characteristics of leakage current of XLPE cable and the influencing factors of detection were analyzed. The experimental results shown that the leakage current of XLPE cable can be detected effectively. The designed sensor can measure leakage current of DC cables accurately with a measurement range of ±30 mA, error less than ±2% and sensitivity up to 1 μA. In terms of factors affecting on-site measurement, the leakage current of XLPE insulated cables was affected by voltage polarity and detection time, and the leakage current under negative polarity voltage was proportional to positive polarity. High, leakage current reading tends to be stable after 200s. This paper studied and realized the detection of DC cable status by leakage current under operating conditions, which laid a foundation for the on-site condition evaluation and maintenance of the cable.

KEYWORDS

DC, giant magnetoresistance effect, XLPE cable, leakage current, sensor