Analysis of Partial Discharge Characteristics in Power Cables with Different Defects Under Power Frequency Voltage

This paper investigates the relationship between partial discharge (PD) behavior and applied voltage for different defect types in power cable insulation systems. A series of power frequency partial discharge tests were conducted. The study revealed that the partial discharge characteristics vary significantly based on the defect type and the applied voltage. For the main insulation knife-cut defect, both the magnitude and number of PD pulses increased steadily with rising voltage. Conversely, the sharp protrusion defect exhibited a decrease in PD activity at higher voltages due to a self-recovery phenomenon, while the conductive residue defect showed irregular PD behavior, reflecting the randomness of the discharge mechanism. These findings contribute to a better understanding of PD mechanisms in cable systems and provide insights for improving defect detection techniques and insulation material development.