空间电荷对脉冲电压下局部放电影响

Space Charge Effects on Partial Discharge Activities Under Pulse Voltage

研究了空间电荷对双极性脉冲电压下局部放电行为的影响。通过等温松弛法测量了纳米和非纳米聚酰亚胺膜的陷阱能级和密度,表明纳米材料中大量界面区的存在导致其陷阱密度和电导率比非纳米材料大;此外,通过测量不同频率和上升时间下的局部放电参量(平均放电量和放电次数等)表明,频率的增加和上升时间的缩短导致PD放电活动增强,纳米材料的放电活动低于非纳米材料。通过不同材料的陷阱参数测量结果,分析了纳米和非纳米材料在脉冲电压下PD特征的不同,其PD特征受到材料陷阱参数的影响。

Relationship between space charge and PD （partial discharge） parameters under bipolar pulse voltage is addressed in this paper. Trap charge parameters （e.g., trapped charge density, trap energy level） in nanocomposites polyimide film and common polyimide film are investigated by isothermal relaxation current method. From comparison of trap parameters between two different materials, it comes out that trapped charge density and conductivity of nanocomposites polyimide is obviously larger than common polyimide film because a large number of interface areas exist in nanocomposites materials. Furthermore, partial discharge parameters （e.g., discharge number, mean discharge quantity） under pulse voltage are measured for nanometer and non nanometer materials. Increase of pulse frequency leads to enhancement of PD activity, whereas increase of rise time of pulse weakens PD activity. Moreover, depending on different trap parameters of two different materials, different PD activities are analyzed. Mobility of space charge has a larger effect on PD activity at pulse voltage.