Partial Discharge Detection Method for XLPE Power Cables Based on a New Electromagnetic Coupling Method

Partial discharge detection is an important means to grasp the insulation condition of XLPE power cables. At present, the sensors used in the traditional electromagnetic coupling method for partial discharge detection of XLPE cables have a narrow working frequency band and are inconvenient to install. In response to this issue, this article has proposed a partial discharge detection method for XLPE power cables based on a new electromagnetic coupling method, has designed a transient magnetic field sensor based on the principle of wideband magnetic field coupling. The performance of the sensor has been tested through laboratory performance testing, onsite simulation testing verification, and on-site inspection. The results show that the working frequency range of the sensor is 0.3～340 MHz、380～1500 MHz, covering the detection frequency bands of high frequency and ultra-high frequency, and covering the main energy range of cable partial discharge signals. The average equivalent height in the frequency range of 300～1500 MHz is 8.9 mm, and the detection sensitivity and signal-to-noise ratio are better than HFCT. In addition, the sensor has a compact structure and easy installation, which can be widely used for partial discharge detection of power cables, switchgear, GIS and other equipment.