The objective of this study was to investigate the behavior of the electrical insulation system of a power cable in the presence of partial discharges (PDs). The cable was taped DH gauge 2 with PTFE insulation, currently used in aircraft. A PD aging chamber has been designed and constructed. The cable specimens were partially covered with grounded shielding braid. Thus, when a voltage exceeding the system partial discharge inception voltage (PDIV) was applied to the center conductor (~30 kHz AC sinusoidal voltage), the insulation system was subjected to partial discharges over a cable length delimited by the dimensions of the ground braid. Accelerated ageing was carried out at room temperature and atmospheric pressure. The conditions for the presence of external discharges (discharges initiated at the ground braid conductors in contact with the outer insulating face of the cable) and internal discharges (discharges initiated in the internal cavities of the insulation at the peripheral strands of the conductor) were identified based on the experimental conditions (amplitude of the applied voltage, geometry of the ground braid). For each aging condition, the mean power dissipated in the discharge was measured, and the delay to failure noted. During aging certain specimens, PDIV was also measured.