油浸绝缘纸损伤与局部放电相位分布模式演化的关系

Relationship Between Damage of Oil-Immersed Paper and Evolution of Phase-Resolved Partial Discharge Patterns

文章对油浸绝缘纸损伤过程中的表面形貌、表面粗糙度、表面电导率和气隙气体与局部放电相位分布(PRPD)模式演化的关系进行了研究。根据PRPD模式变化将放电损伤过程划分为五个阶段,利用显微镜、扫描电镜、原子力显微镜、高阻仪和气体测量装置,对比分析了每一阶段的表面损伤情况及气隙气体变化。研究结果表明:五个损伤阶段中,电负性气体含量交替下降上升,气隙内的主要放电形式在亚辉光(或辉光)放电和脉冲放电之间交替转换;亚辉光放电的PRPD模式主要由生成的弱电负性气体自身性质决定;脉冲放电的PRPD模式主要由表面损伤决定;脉冲放电的PRPD模式均拥有不同程度的"兔耳"特征和周期特征,"兔耳"特征强弱主要由表面电导率决定,周期特征强弱主要由表面陷阱密度决定;表面粗糙度不改变PRPD模式形状,但随着其值下降放电量呈上升趋势。

This paper respectively studies relationships between evolution of phase-resolved partial discharge（PRPD） patterns and surface topography,surface roughness,surface conductivity of oil-immersed insulation paper and gas constituents within cavity during the damaging process caused by partial discharge（PD）.According to PRPD patterns,the damaging process can be divided into five stages.At each stage,surface conditions of insulation are analyzed by optical microscopy,scanning electron microscopy,atomic force microscopy,and high-resistance meter.Gas volume is analyzed by gas-measuring model,as well.Meanwhile,PRPD patterns of different gas constitution are compared,and analyzed,as well as those of different surface-damaging conditions.The results reveal that during the damaging process,main discharging form within cavity alters between pseudo-glow（or glow） and spark;PRPD pattern for pseudo-glow chiefly depends on properties of weak electronegative gases generated during PD;while PRPD patterns for spark mainly determined by different surface damage conditions;PRPD patterns for spark manifest different levels of ＂rabbit-ear＂ and periodical features,whose levels mainly depends on surface trap density and surface conductivity,respectively,surface roughness will not change shapes of PRPD patterns,but discharge amount declines as its value increases.