High frequency partial discharge measurement by capacitive sensor for underground power cable system

This paper deals with partial discharge (PD) measurement technique on the range of high frequency by capacitive sensor for the power cable system. This sensor is installed inside of cable joints and terminations without affecting the insulation design. The sensitivity of the sensor depending on the installation condition was investigated by simulation and compared with the results of experiments with joint occurring PD. It was shown that the dominant factor affecting sensitivity of the sensor was resistance formed between sensor and ground sheath. It was proven that the sensitivity of this sensor was much higher than that of the conventional method in accordance with IEC270 standard. This sensor is available for the on-line PD monitoring system.