带电雨凇覆冰铝管起晕电压下降趋势研究(英文)

Research on the Decrease Trend in Corona Onset Voltage of Aluminum Conductor After Energized Glaze Icing

雨凇覆冰后的铝管表面会生长尖锐的冰柱从而影响导线电晕起始特性;目前国内外针对导线覆冰做了大量研究,但往往忽略运行导线带电覆冰的事实,且尚未深入研究带电覆冰后的导线起晕电压跌落规律。因此,在低温低气压试验室进行了铝管带电雨凇覆冰后的交流电晕试验,利用紫外成像技术及曲线拟合法测量分析了不同雨凇形态下对应的起晕电压值,并根据不同雨凇冰柱形态建立有限元模型分析铝管电场的畸变规律。结果表明:雨凇覆冰会严重降低导线起晕电压;不同电场雨凇覆冰后的铝管起晕电压也不同;覆冰时间的增加会导致起晕电压出现连续降低,但降低速度逐渐减慢;较高的覆冰水电导率不会改变雨凇覆冰形态,但会导致起晕电压逐渐降低;雨凇冰柱越长越尖则引起越严重的电场畸变,起晕电压也越低。所得结论可为雨凇频发地区输电线路的设计提供理论依据。

Glaze icicles will grow on conductor surfaces and affect its corona onset voltage（COV）. Although many researches on icing conductors have been done, they always neglect the fact that the energized icing and no lights have been thrown into decrease regularities of COV values. Therefore, the AC corona discharge tests of smooth conductors after icing were implemented in the Multifunction Climate Chamber while the UV imaging camera and I-U curve fitting were applied to measure and analyze COV values. The finite element models were established to research how the icicles affect electric field on conductor surfaces. Results show that glaze will reduce conductor COV significantly. Different glaze shapes lead to distinct COV values. Increasing the icing time will lessen COV values with the drop rate slowing down. Higher conductivity causes the decline of COV without changing glaze morphology. The sharper the icicles are, the more seriously the field distorted and the lower the COV values are. The results can provide references for selection and design of the transmission lines in glaze icing areas.