短路电弧向潜供电弧转换过程中,因短路电弧直径远大于潜供电弧,潜供电弧出现的具体位置不能确定,潜供电弧初始位置具有随机性。针对这一问题首次建立了仿真模型,认为潜供电弧出现的位置与空间电导率有关,电导率越大,越容易击穿形成潜供...短路电弧向潜供电弧转换过程中,因短路电弧直径远大于潜供电弧,潜供电弧出现的具体位置不能确定,潜供电弧初始位置具有随机性。针对这一问题首次建立了仿真模型,认为潜供电弧出现的位置与空间电导率有关,电导率越大,越容易击穿形成潜供电弧。基于此种认识,计算了空气电导率与温度之间的关系,进一步求得了不同短路电流下电导率沿电弧径向分布规律。在此基础上,仿真计算了不同短路电流下潜供电弧初始弧长的随机性,进而将潜供电弧初始位置随机性模型应用到链式电弧模型中,对潜供电弧进行仿真计算,获得了具有分散性的潜供电弧燃弧时间,并将仿真结果与实验结果相比较。结果表明:电导率随温度变化呈先增加后平坦最终降低的规律;电流为1 k A时电导率沿电弧径向单调递减,而电流为25 k A时电导率沿电弧径向呈现先增加后减小的趋势;随着短路电流的增大,潜供电弧初始弧长平均值与弧长的分散性也随之增大;燃弧时间计算结果与实验结果整体趋势一致,相对误差较小,计算模型可靠。展开更多
Secondary arc discharge is a complicated physical phenomenon and one of the key fundamental issues associated with ultra high voltage （UHV） half-wavelength transmission lines （HWTL）. With the establishment of a ph...Secondary arc discharge is a complicated physical phenomenon and one of the key fundamental issues associated with ultra high voltage （UHV） half-wavelength transmission lines （HWTL）. With the establishment of a physicM simulation platform for the HWTLs, experiments were carried out regarding the motion and extinction characteristics of secondary arcs. The cathode arc root and the anode arc root were found to show an obvious polarity effect while the arc column was moving in a spirM, due to their different motion mechanisms. The extinction behavior was also recorded and experiments were designed with different compensation conditions. Results show that the arcing time can be greatly reduced if there exists an electrical compensation network. The research provides fundamentals for understanding the physics involved, especially the motion and extinction mechanisms of the secondary arcs.展开更多
The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low- voltage physical experimental pl...The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low- voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines.展开更多
文摘短路电弧向潜供电弧转换过程中,因短路电弧直径远大于潜供电弧,潜供电弧出现的具体位置不能确定,潜供电弧初始位置具有随机性。针对这一问题首次建立了仿真模型,认为潜供电弧出现的位置与空间电导率有关,电导率越大,越容易击穿形成潜供电弧。基于此种认识,计算了空气电导率与温度之间的关系,进一步求得了不同短路电流下电导率沿电弧径向分布规律。在此基础上,仿真计算了不同短路电流下潜供电弧初始弧长的随机性,进而将潜供电弧初始位置随机性模型应用到链式电弧模型中,对潜供电弧进行仿真计算,获得了具有分散性的潜供电弧燃弧时间,并将仿真结果与实验结果相比较。结果表明:电导率随温度变化呈先增加后平坦最终降低的规律;电流为1 k A时电导率沿电弧径向单调递减,而电流为25 k A时电导率沿电弧径向呈现先增加后减小的趋势;随着短路电流的增大,潜供电弧初始弧长平均值与弧长的分散性也随之增大;燃弧时间计算结果与实验结果整体趋势一致,相对误差较小,计算模型可靠。
基金supported by National Natural Science Foundation of China(No.51277061)the National High Technology Research and Development Program of China(No.2011AA05A121)
文摘Secondary arc discharge is a complicated physical phenomenon and one of the key fundamental issues associated with ultra high voltage （UHV） half-wavelength transmission lines （HWTL）. With the establishment of a physicM simulation platform for the HWTLs, experiments were carried out regarding the motion and extinction characteristics of secondary arcs. The cathode arc root and the anode arc root were found to show an obvious polarity effect while the arc column was moving in a spirM, due to their different motion mechanisms. The extinction behavior was also recorded and experiments were designed with different compensation conditions. Results show that the arcing time can be greatly reduced if there exists an electrical compensation network. The research provides fundamentals for understanding the physics involved, especially the motion and extinction mechanisms of the secondary arcs.
基金supported by National Natural Science Foundation of China(Nos.51277061 and 51420105011)
文摘The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low- voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines.
