An efficient strategy triggered crosslinking of polyethylene and its application in degassing-free ultrahigh voltage power cables

Polyethylene has excellent electrical insulation, but its low thermal stability and breakdown strength limit its application in the field of high-voltage (HV) and ultrahigh voltage (UHV) power cables. In this work, we have developed a new organic peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane (Bi25), which can efficiently trigger the crosslinking of polyethylene (Bi25-XLPE). Bi25-XLPE does not produce gas byproducts and has a longer scorching time. All performance of Bi25-XLPE sheets fulfill the standard of the 500 kV power cable insulation due to the void-free nature, higher crosslinking density and crystallinity. In addition, one 500 kV power cable model was constructed by COMSOL, which confirmed the breakdown strength (up to 61.66 kV/mm) and stability of Bi25-XLPE.

Automated summary

Polyethylene has limitations in HV/UHV power cables due to its low thermal stability and breakdown strength, despite its excellent electrical insulation. A new organic peroxide, Bi25, has been developed to efficiently trigger the crosslinking of polyethylene (Bi25-XLPE). Bi25-XLPE, with void-free nature, higher crosslinking density, and crystallinity, meets the insulation standard for 500 kV power cables. The breakdown strength (up to 61.66 kV/mm) and stability of Bi25-XLPE are confirmed by a constructed 500 kV power cable model using COMSOL.