Cross linked polyethylene (XLPE) power cable is widely used in transmission and distribution network and

however

suffers from long-term aging degradation under continuous electrical stress

and cable aging can easily cause insulation breakdown. In order to improve the online assessment technology of cable insulation aging status

a three-core tube-type cable grounding current phase angle calculation model considering uneven aging of cable insulation is set up based on PSCAD. The phase angle characteristics of such three types of the grounding wire current as single-phase uneven aging

two-phase uneven aging and three-phase uniform aging are obtained through FFT variation. The result shows that compared to the current of steel armored grounding wires

the response of phase angle of shielding wire current to the aging characteristics is more sensitive. For the single-phase aging

the dielectric constant increases from 2 to 5

and the phase angle of the shielding wire current increases from -51.01° to -50.6°. For the two-phase aging

the amplitude of phase angle gradually increases with the increase of degree of aging; For the three-phase uniform aging

the phase angle increment of the shielding wire current is 0.24° compared to normal cables and

at the same time

the phase angle increment of the shielding wire current is maximum compared to single-phase aging and two-phase aging with the same dielectric constant of 2.8 (0.15° for single-phase aging and 0.17° for two-phase aging). The analysis of the phase amplitude of the shielded wire current can not only judge the aging status of the cable insulation

but also distinguish the aging phase and degree. The research results in this paper can provide important theoretical basis for assessing the insulation aging level of cables through the phase angle of grounding wire current.