Open AccessSpace charge behaviors in cable insulation under a direct current‐superimposed pulsed electric field
Author(s) -
He Dongxin,
Zhang Tao,
Meng Fansong,
Li Qingquan,
Wang Wei,
Liu Hongshun,
Teyssedre Gilbert
Publication year - 2021
Publication title -
high voltage
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.732
H-Index - 20
ISSN - 2397-7264
DOI - 10.1049/hve2.12032
Subject(s) - electric field , space charge , voltage , high voltage direct current , materials science , direct current , electrical engineering , amplitude , mechanics , pulsed dc , high voltage , physics , engineering , optics , electron , nanotechnology , sputter deposition , thin film , sputtering , quantum mechanics
When high‐voltage direct current (HVDC) cables are subjected to a direct current(DC)‐superimposed pulsed electric stress, the pulsed voltage applied facilitates electrical tree generation and breakdown; however, the mechanism involved remains unclear. To study the deterioration mechanism of cable insulation under a pulsed electric field, an experiment on the dynamic characteristics of space charge under a DC‐superimposed pulsed electric field was conducted. For this experiment, a pulsed time trigger control circuit was developed to accurately measure the change law of the space charge in cross‐linked polyethylene samples at the rising and falling edges of the pulsed electric field. The experimental results showed an unusual change law: the space charge density increases with falling voltage amplitude and decreases with rising voltage amplitude. The sudden change in the electric field breaks the balance of the forces acting on the space charge, leading to injection, extraction and migration. The energy released during these dynamic processes may destroy the microstructure of the insulation material and contributes to the growth of the electrical tree. This study provides an insight on the initiation mechanism of electrical tree in HVDC cables and proposes a strategy to suppress electrical tree initiation.