低温下硅橡胶直流击穿特性变化规律研究

Study on Change Regularity of DC Breakdown Characteristics of Silicone Rubber at Low Temperature

为了研究硅橡胶绝缘材料低温环境下直流击穿特性的变化,采用恒温试验箱对硅橡胶材料进行低温冷冻,利用球球电极与棒板电极模拟不均匀电场,试验测定不同温度下、不同氢氧化铝含量硅橡胶材料的直流击穿电压随温度的变化规律,分析了其中的原因机理,并测量了体积电阻率。试验结果表明:随着温度的降低,硅橡胶材料的直流击穿呈现出先增大后趋于稳定的特性;在相同的低温处理下,氢氧化铝质量分数为130%的硅橡胶样品具有最大的直流击穿电压;施加正极性直流电压时,硅橡胶绝缘材料的击穿电压略小于施加负极性直流电压时的击穿电压。

To understand the variation of DC breakdown characteristics of silicone rubber insulation materials,sili-cone rubber materials were frozen at low temperature in a constant-temperature test chamber. Ball-ball electrode and rod-plate electrode were employed to simulate the nonuniform electric field. The change regularity of DC break-down voltage of silicon rubber with different aluminum hydroxide contents with temperature was measured,and cor-responding mechanism was analyzed. And the volume resistivity was also measured. Results show that: 1)with the temperature lowering,the DC breakdown voltage of the silicone rubber material rises first and then tends to be sta-ble;2)for the same low temperature treatment,the DC breakdown voltage of the silicone rubber with relative con-tent of 130%aluminum hydroxide gets the maximum;and 3)applying positive polarity DC voltage,the breakdown voltage of the silicone rubber insulation material is smaller,compared with that under negative polarity DC voltage.