The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it ...The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.展开更多
Thermal ageing is an important factor leading to the deterioration of crosslinked polyethylene(XLPE)cable insulation.In this paper,XLPE insulating material was prepared in the laboratory and treated by thermal ageing ...Thermal ageing is an important factor leading to the deterioration of crosslinked polyethylene(XLPE)cable insulation.In this paper,XLPE insulating material was prepared in the laboratory and treated by thermal ageing at 130℃ for durations of up to 40 days.Space charge and DC electrical breakdown characteristics were investigated to evaluate the DC electrical performance of differently aged XLPE.Furthermore,to gain deeper insight into the underlying mechanisms,the charge trap characteristics along with the chemical and crystalline structures were examined.The results show that,during the effective protection period of the antioxidant,the XLPE samples exhibit enhanced DC electrical performance,specifically higher DC breakdown strength and reduced space charge accumulation.This improvement is attributed to the evolution of the microstructure.In the initial ageing stage,the degree of crystallisation increases,whereas physicochemical defects are reduced,accompanied by a more concentrated trap energy distribution.As a result,charge injection and migration are effectively inhibited.In the later stage of ageing,the antioxidant efficacy weakens and molecular chain scission occurs,resulting in the disappearance of spherulitic structure and deterioration of electrical properties.These findings are essential for the understanding of the XLPE cable service performance and the enhancement of the XLPE DC electrical performance.展开更多
基金Major Research Project of Shanghai City(No. 045211024)
文摘The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.
基金supported by the Science and Technology Project of State Grid Corporation of China(Grant SGSNKY00KJJS2100283).
文摘Thermal ageing is an important factor leading to the deterioration of crosslinked polyethylene(XLPE)cable insulation.In this paper,XLPE insulating material was prepared in the laboratory and treated by thermal ageing at 130℃ for durations of up to 40 days.Space charge and DC electrical breakdown characteristics were investigated to evaluate the DC electrical performance of differently aged XLPE.Furthermore,to gain deeper insight into the underlying mechanisms,the charge trap characteristics along with the chemical and crystalline structures were examined.The results show that,during the effective protection period of the antioxidant,the XLPE samples exhibit enhanced DC electrical performance,specifically higher DC breakdown strength and reduced space charge accumulation.This improvement is attributed to the evolution of the microstructure.In the initial ageing stage,the degree of crystallisation increases,whereas physicochemical defects are reduced,accompanied by a more concentrated trap energy distribution.As a result,charge injection and migration are effectively inhibited.In the later stage of ageing,the antioxidant efficacy weakens and molecular chain scission occurs,resulting in the disappearance of spherulitic structure and deterioration of electrical properties.These findings are essential for the understanding of the XLPE cable service performance and the enhancement of the XLPE DC electrical performance.
