Charge dynamics at interfaces in high voltage direct current(HVDC)cable joints consisting of cable,joint insulation and lubricant may have an impact on the overall joint reliability.Although interactions between diffe...Charge dynamics at interfaces in high voltage direct current(HVDC)cable joints consisting of cable,joint insulation and lubricant may have an impact on the overall joint reliability.Although interactions between different lubricants and the joint insulation have been studied in recent years,the effect of lubricant diffusion on the electrical properties and charge dynamics at interfaces remains unclear and is therefore investigated in this paper.Different lubricants were applied at the interface of crosslinked polyethylene(XLPE)and silicone rubber(SIR)samples,and mass,electrical conductivity,and space charge were measured over a 96 h ageing period.The mass of the samples was found to exhibit nonmonotonic behaviour,indicating complex interactions between the lubricant and material.XLPE experiences a decrease in conductivity while there is an increase in conductivity for SIR,which is linked to the migration of lubricant and therefore changes in trap distribution.Space charge measurements indicate changes in trap characteristics,which depend strongly on the used type of lubricant.The findings highlight that lubricant diffusion affects both the bulk properties and charge accumulation at the interface,and underline the large effect of the type of lubricant.These results are crucial for understanding the long-term performance of cable joints and insulating materials in HVDC cable systems.展开更多
电缆接头是确保电力电缆实现高效稳定电能传输的关键部件,但其薄弱的绝缘性能却导致电缆故障频发,这主要与其界面处的缺陷相关。以220 k V电缆接头为研究对象,基于COMSOL多物理场有限元仿真,研究导电杂质、气隙和水滴3种典型绝缘缺陷的...电缆接头是确保电力电缆实现高效稳定电能传输的关键部件,但其薄弱的绝缘性能却导致电缆故障频发,这主要与其界面处的缺陷相关。以220 k V电缆接头为研究对象,基于COMSOL多物理场有限元仿真,研究导电杂质、气隙和水滴3种典型绝缘缺陷的不同尺寸及位置对电-热场分布的影响。结果表明,接头界面处的热场分布主要受热导率影响,相较于导电杂质与水滴,空气更低的热传导效率使得缺陷处出现更明显的局部温升,而受尺寸与位置的影响则相对较小。电场分布则受相对介电常数的影响较大,与绝缘材料相比,导电杂质与水滴较高的介电参数会导致其界面位置的电场先衰减后升高,最终形成强电场畸变点。而气隙附近的电场均会产生较大幅度的升高,畸变的范围更广,程度更大。展开更多
文摘Charge dynamics at interfaces in high voltage direct current(HVDC)cable joints consisting of cable,joint insulation and lubricant may have an impact on the overall joint reliability.Although interactions between different lubricants and the joint insulation have been studied in recent years,the effect of lubricant diffusion on the electrical properties and charge dynamics at interfaces remains unclear and is therefore investigated in this paper.Different lubricants were applied at the interface of crosslinked polyethylene(XLPE)and silicone rubber(SIR)samples,and mass,electrical conductivity,and space charge were measured over a 96 h ageing period.The mass of the samples was found to exhibit nonmonotonic behaviour,indicating complex interactions between the lubricant and material.XLPE experiences a decrease in conductivity while there is an increase in conductivity for SIR,which is linked to the migration of lubricant and therefore changes in trap distribution.Space charge measurements indicate changes in trap characteristics,which depend strongly on the used type of lubricant.The findings highlight that lubricant diffusion affects both the bulk properties and charge accumulation at the interface,and underline the large effect of the type of lubricant.These results are crucial for understanding the long-term performance of cable joints and insulating materials in HVDC cable systems.
文摘电缆接头是确保电力电缆实现高效稳定电能传输的关键部件,但其薄弱的绝缘性能却导致电缆故障频发,这主要与其界面处的缺陷相关。以220 k V电缆接头为研究对象,基于COMSOL多物理场有限元仿真,研究导电杂质、气隙和水滴3种典型绝缘缺陷的不同尺寸及位置对电-热场分布的影响。结果表明,接头界面处的热场分布主要受热导率影响,相较于导电杂质与水滴,空气更低的热传导效率使得缺陷处出现更明显的局部温升,而受尺寸与位置的影响则相对较小。电场分布则受相对介电常数的影响较大,与绝缘材料相比,导电杂质与水滴较高的介电参数会导致其界面位置的电场先衰减后升高,最终形成强电场畸变点。而气隙附近的电场均会产生较大幅度的升高,畸变的范围更广,程度更大。
