Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The ar...Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes major erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.展开更多
为弥补传统型式试验项目对断路器弧触头状态检测的缺失,文中提出了一种利用动静触头之间动态电阻曲线诊断弧触头状态的方法。试验通过断路器合成试验回路电流源部分对某试品断路器进行了从开断额定短路电流(有效值40 k A)零次到额定次数...为弥补传统型式试验项目对断路器弧触头状态检测的缺失,文中提出了一种利用动静触头之间动态电阻曲线诊断弧触头状态的方法。试验通过断路器合成试验回路电流源部分对某试品断路器进行了从开断额定短路电流(有效值40 k A)零次到额定次数(22次)的烧蚀老化试验,每次烧蚀后测量其弧触头动态电阻曲线,并将与零烧损状态的曲线之间的相关系数作为弧触头烧损状态诊断的特征参数,从测试结果中发现在断路器第15次开断之后相关系数开始出现明显的变化,该现象表明弧触头寿命已经接近工作极限。试验结果证明,动态电阻曲线能够很好地反映出弧触头的烧损情况,是一种有效的SF6断路器弧触头状态诊断方法。展开更多
A uniform transient temperature field model of electrical contacts operation was found by analyzing the process of closing arc constriction resistance Joule heat ~ breaking arc. Essential parameters of Ag/La2NiO4 elec...A uniform transient temperature field model of electrical contacts operation was found by analyzing the process of closing arc constriction resistance Joule heat ~ breaking arc. Essential parameters of Ag/La2NiO4 electrical contact material for transient temperature field calculation were obtained through tests of electrical contact experimental instrument under 18 V DC in different cur- rents, other correlation experiments, and calculation anal- ysis. The finite element method was applied to solve the transient temperature field, and the features and distribution of the transient temperature field were obtained. The condition of material erosion and mass transfer can be forecasted by those calculation results. It is beneficial to research about the lifetime of Ag/La2NiO4 electrical material.展开更多
Arc erosion morphologies of Ag/MeO（10） electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope（SE...Arc erosion morphologies of Ag/MeO（10） electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope（SEM） and a 3D optical profiler（3DOP）. The results indicated that 3DOP could supply clearer and more detailed arc erosion morphology information. Arc erosion resistance of Ag/SnO_2（10） electrical contact material was the best and that of Ag/CuO（10） was the worst. Arc erosion morphology of Ag/MeO（10） electrical contact materials mainly included three different types. Arc erosion morphologies of Ag/ZnO（10） and Ag/SnO_2（10） electrical contact materials were mainly liquid splash and evaporation, and those of Ag/CuO（10） and Ag/CdO（10） were mainly material transfer from anode to cathode. Arc erosion morphology of Ag/SnO_2（6）In_2O_3（4） electrical contact materials included both liquid splash, evaporation and material transfer. In addition, the formation process and mechanism on arc erosion morphology of Ag/MeO（10） electrical contact materials were discussed.展开更多
宁夏福祥变220 k V电流互感器因绝缘外套严重电蚀损缺陷而退运。福祥变地区气候干燥,降雨少,雾日少,互感器外套的电蚀损现象无法用常规污闪理论模型解释。从污秽分析、材料分析、电磁场计算3个方面,对互感器复合外套电蚀损缺陷进行了分...宁夏福祥变220 k V电流互感器因绝缘外套严重电蚀损缺陷而退运。福祥变地区气候干燥,降雨少,雾日少,互感器外套的电蚀损现象无法用常规污闪理论模型解释。从污秽分析、材料分析、电磁场计算3个方面,对互感器复合外套电蚀损缺陷进行了分析,并且在实验室中模拟出了材料表面放电及蚀损现象,验证了原因分析的结论:福祥变地区积污严重,污秽中含可导电颗粒;互感器绝缘外套硅橡胶材料憎水性良好,主要元素含量未发生明显变化;互感器护套低压端伞裙设计存在缺陷,低压端法兰与护套伞裙直接相连导致连接处液体硅橡胶材料运行场强过高诱发放电。特殊污秽条件以及伞裙设计缺陷是互感器外套缺陷的主要原因。展开更多
基金Barnbrook Systems, UK for their support of this work
文摘Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes major erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.
文摘为弥补传统型式试验项目对断路器弧触头状态检测的缺失,文中提出了一种利用动静触头之间动态电阻曲线诊断弧触头状态的方法。试验通过断路器合成试验回路电流源部分对某试品断路器进行了从开断额定短路电流(有效值40 k A)零次到额定次数(22次)的烧蚀老化试验,每次烧蚀后测量其弧触头动态电阻曲线,并将与零烧损状态的曲线之间的相关系数作为弧触头烧损状态诊断的特征参数,从测试结果中发现在断路器第15次开断之后相关系数开始出现明显的变化,该现象表明弧触头寿命已经接近工作极限。试验结果证明,动态电阻曲线能够很好地反映出弧触头的烧损情况,是一种有效的SF6断路器弧触头状态诊断方法。
基金financially supported by the National Science Foundation of China-Yunnan United Foundation(No.U0837601)the National Natural Science Foundation of China(No.51267007)the Natural Science Foundation of Yunnan Province(No.2010CD126,No.2012FB195)
文摘A uniform transient temperature field model of electrical contacts operation was found by analyzing the process of closing arc constriction resistance Joule heat ~ breaking arc. Essential parameters of Ag/La2NiO4 electrical contact material for transient temperature field calculation were obtained through tests of electrical contact experimental instrument under 18 V DC in different cur- rents, other correlation experiments, and calculation anal- ysis. The finite element method was applied to solve the transient temperature field, and the features and distribution of the transient temperature field were obtained. The condition of material erosion and mass transfer can be forecasted by those calculation results. It is beneficial to research about the lifetime of Ag/La2NiO4 electrical material.
基金Project(2012QNZT003)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2012M521542)supported by the Postdoctoral Science Foundation of China+1 种基金Project(14JJ3014)supported by the Hunan Provincial Natural Science Foundation of ChinaProject(BSh1202)supported by the Zhejiang Provincial Postdoctoral Scientific Research Foundation of China
文摘Arc erosion morphologies of Ag/MeO（10） electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope（SEM） and a 3D optical profiler（3DOP）. The results indicated that 3DOP could supply clearer and more detailed arc erosion morphology information. Arc erosion resistance of Ag/SnO_2（10） electrical contact material was the best and that of Ag/CuO（10） was the worst. Arc erosion morphology of Ag/MeO（10） electrical contact materials mainly included three different types. Arc erosion morphologies of Ag/ZnO（10） and Ag/SnO_2（10） electrical contact materials were mainly liquid splash and evaporation, and those of Ag/CuO（10） and Ag/CdO（10） were mainly material transfer from anode to cathode. Arc erosion morphology of Ag/SnO_2（6）In_2O_3（4） electrical contact materials included both liquid splash, evaporation and material transfer. In addition, the formation process and mechanism on arc erosion morphology of Ag/MeO（10） electrical contact materials were discussed.
文摘宁夏福祥变220 k V电流互感器因绝缘外套严重电蚀损缺陷而退运。福祥变地区气候干燥,降雨少,雾日少,互感器外套的电蚀损现象无法用常规污闪理论模型解释。从污秽分析、材料分析、电磁场计算3个方面,对互感器复合外套电蚀损缺陷进行了分析,并且在实验室中模拟出了材料表面放电及蚀损现象,验证了原因分析的结论:福祥变地区积污严重,污秽中含可导电颗粒;互感器绝缘外套硅橡胶材料憎水性良好,主要元素含量未发生明显变化;互感器护套低压端伞裙设计存在缺陷,低压端法兰与护套伞裙直接相连导致连接处液体硅橡胶材料运行场强过高诱发放电。特殊污秽条件以及伞裙设计缺陷是互感器外套缺陷的主要原因。
