Inhibition of electrical trees degradation of crosslinked polyethylene at high temperatures by electron‐buffering voltage stabilizers

Abstract

The effect of adding electron-buffering voltage stabilizer (1 wt% maminobenzoic acid) on the electrical tree-induced degradation of cross-linked polyethylene (XLPE) was studied at high temperatures. The electrical tree inception, growth, and partial discharge characteristics were simultaneously analyzed at 30, 50, and 70 C, respectively. The results showed that the growth rate of electrical tree and partial discharge activity as well as the discharge repetition rate, significantly increased with the temperature for pure XLPE and XLPE stabilizer blend. However, the XLPE stabilizer blend exhibited higher tree inception voltage, lower tree growth rate, and partial discharge activity than pure XLPE. The addition of the voltage stabilizer reduced the carbon layer thickness in the tree channel and offered higher resistance to the electrical tree growth. Surface potential decay demonstrated that the voltage stabilizer addition decreased the trap energy level, but increased the shallow trap density of the XLPE. Quantum chemical calculations showed that the voltage stabilizer enhanced the ability to buffer the high-energy electrons in the XLPE. A high-energy electron buffering mechanism was also proposed to explain the effect of voltage stabilizer on the electrical treeing and partial discharge activity in the XLPE at high temperatures.

Regulating the structure of crosslinked polyethylene and its application in ultra‐high voltage cables

“…Adding voltage stabilizers to the insulation prevents the electric field from being distorted at high voltages, 33,34 and changing the crosslinking method by using different crosslinkers also stabilizes the electric field. To investigate the electrical properties of the insulation layer after crosslinking initiated by various crosslinkers, we calculated the distribution of potential in the insulation layer using COMSOL Multiphysics (Figure 5A).…”

“…Adding voltage stabilizers to the insulation prevents the electric field from being distorted at high voltages, 33,34 and changing the crosslinking method by using different crosslinkers also stabilizes the electric field.…”

Design of voltage stabilizers for high breakdown strength materials

“…One approach to the development of new high breakdown strength material is compounding voltage stabilizer molecules into polyethylene, which can then be further crosslinked. [2][3][4][5][6][7][8][9] Chen and co-workers 7 have also tried to use nanofillers in cross-linked polyethylene and found that the addition of nanofillers typically will decrease the electrical insulation performance. The study of voltage stabilizers has a history of more than half a century.…”

“…Cross‐linked polyethylene is an important and widely utilized material for power transmission cables. One approach to the development of new high breakdown strength material is compounding voltage stabilizer molecules into polyethylene, which can then be further cross‐linked 2–9 . Chen and co‐workers 7 have also tried to use nanofillers in cross‐linked polyethylene and found that the addition of nanofillers typically will decrease the electrical insulation performance.…”

Mechanistic insights into the thermal–mechanical aging of the interface of cross‐linked polyethylene/silicone rubber

“…In recent years, the urgent requirement for offshore wind power transmission and urbanization has led to the development of power cables (mainly cross-linked polyethylene [XLPE] cables). [1][2][3][4] With the continuous increase in voltage levels, frequent failures occur in cable accessories, due to their complex structures and challenges in multilayered insulation coordination. This significantly constrains the stable operation of power systems.…”