基于去极化电流的变压器复合绝缘材料表面空间电荷入陷、脱陷行为研究  

Study on Charge Trapping and Release of Polymer Material Based on Depolarization Current

作　　者：李雄伟[1] LI Xiong-wei(Yan’an Vocational and Technical College,Yan'an 716000,Shaanxi,China)

机构地区：[1]延安职业技术学院,陕西延安716000

出　　处：《合成材料老化与应用》2020年第2期65-69,共5页Synthetic Materials Aging and Application

摘　　要：变压器复合绝缘材料中空间电荷的积累会加速材料的老化,甚至导致变压器材料绝缘性能失效,而温度对聚合物绝缘材料空间电荷入陷和脱陷性能的影响尚存争议。为此本文首先根据应力样品的去极化特性,探讨了低密度交联聚乙烯(LDPE)的电荷入陷和脱陷特性;然后建立了数学模型,该模型从去极化电流出发,根据电荷在样品中的陷阱能级计算出电荷分布;同时在不同温度下试验研究温度对电荷分布的影响。结果表明:材料入陷电荷量随温度升高而增加;电荷分布在性质上接近指数级,即能级较高的入陷的电荷量要比能级较低的少得多;在较高的温度下电荷更易脱陷。温度在绝缘材料电荷注入、陷阱形成、入陷和脱陷的过程中起着不可忽视的作用。The accumulation of space charge in composite insulating materials will accelerate the aging of materials and even lead to the failure of insulating properties. However, the influence of temperature on the space charge sinking and collapse properties of polymer insulating materials is still controversial. Based on the depolarization characteristics of stress samples, the charge trapping and de-trapping characteristics of low density crosslinked polyethylene(LDPE) were discussed in this paper. Then a mathematical model was established. The model calculates the charge distribution according to the trap energy level of the charge in the sample from the depolarization current. At the same time, the effect of temperature on the charge distribution was studied experimentally at different temperatures. The results showed that the amount of trapped charges increased with the increase of temperature, and the distribution of charges was close to exponential level in nature: that is, the amount of trapped charged with higher energy level was much less than that with lower energy level, and the charge was easier to collapse at higher temperature. The results show that temperature plays an important role in charge injection, trap formation, trapping and de-trapping of insulating materials.

关 键 词：空间电荷分布 变压器 去极化电流 温度耦合 

分 类 号：TM451[电气工程—电器]