温度变化对SF_6/N_2混合气体放电特性的影响  

Effect of Temperature Variation on Discharge Characteristics of SF_6/N_2 Gas Mixtures

作　　者：李峰[1] 张潇[1] 张周胜[1] 

机构地区：[1]上海电力学院电气工程学院,上海200090

出　　处：《高电压技术》2017年第3期736-742,共7页High Voltage Engineering

基　　金：上海绿色能源并网工程技术研究中心项目(13DZ2251900)~~

摘　　要：不同温度下SF_6/N_2混合气体的周围离子平均自由行程和热运动速度不同,使SF_6/N_2混合气体放电过程呈现不同特性。为此,在极不均匀电场、雷电冲击电压下研究了温度对SF_6/N_2混合气体放电特性的影响。在正负极性的雷电冲击电压下分别测量冲击击穿电压和预放电电流波形,并分析了不同温度下SF_6/N_2混合气体的预放电现象、步长时间、电晕起始场强及击穿场强。此时试验温度范围设为-20~20℃。结果表明:步长时间、电晕起始场强、击穿场强呈现较大的随机性。负极性雷电冲击电压下步长时间均长于正极性雷电冲击电压下步长时间。负极性冲击电压下10%SF_6-90%N_2混合气体的电晕起始场强和击穿场强随着温度升高而增高。本研究结果对柜式气体绝缘开关设备和气体绝缘金属封闭输电线路设计具有一定的研究意义。The ions mean free path and the thermal motion speeds are different at different temperatures around SF6/N2 mixed gas, thus SF6/N2 mixed gas discharge exhibits a different characteristics. Therefore, under the severe non-uniform electric field and lightning impulse voltage,we studied the breakdown characteristics of SF6/N2 mixed gas along with the temperature change .Moreover, under the positive and negative polarity of lightning impulse voltage, we measured the impulse breakdown voltage and pre-discharge current waveforms, and analyzed the pre-discharge phenomenon, stepping time, corona onset electric field, and breakdown strength in SF6/N2 mixed gas at different temperatures. The temperature range during experiment was set from -20℃ to 20 ℃. Results show that the stepping time, corona onset electric field strength, and breakdown field strength present great randomness. The stepping time under negative polarity impulse voltage is longer than that under positive polarity impulse voltage. Under the negative polarity impulse voltage, as the temperature increases, the corona onset electric field and the breakdown strength of 10%SF6-90%N2 mixed gas will increase. The results are of certain research significance in the design of cubicle gas insulated switchgear and gas insulated metal-enclosed transmission line.

关 键 词：冲击电压 电晕起始场强 击穿场强 SF6/N2混合气体 步长时间 温度变化 

分 类 号：TM21[一般工业技术—材料科学与工程]