Summary
The paper considers a phenomenon earlier observed when investigating the dielectric response of field-aged XLPE-insulated medium-voltage (12/20 kV) cables in order to assess the aging condition. A significant increase of the dissipation factor over a wide range of frequencies was observed when high voltage with low frequency was applied to the cables. This effect is assumed to be caused by trapping of charges in the insulation. The increase of the dissipation factor after voltage loading can also be observed for new cables. On the contrary, some field-aged cables do not show any sensitivity of the dissipation factor to voltage loading. The dissipation factor is most significantly enhanced after application of a +20 kV DC voltage and, to a minor degree, of 20 kV VLF sinus or 20 kV VLF cosine-rectangular voltage. The effect is reversible when the specimen is heated and short circuited after the voltage treatment. The detrapping of space charges can be detected as an emitted current during the heating process.
Additional informations
| Publication type | ISH Collection |
|---|---|
| Reference | ISH2015_556 |
| Publication year | 2015 |
| Publisher | ISH |
| File size | 1 MB |
| Price for non member | Free |
| Price for member | Free |
Authors
Xu Sen, Nourirad Ghasem, Wang Guoli, Gao Chao
