Zhang Zhongyuan, Qi Junwei, Liu Hechen, Wang Wanxian, Zhang Mingjia, Wu Xuan
Hebei Provincial Key Laboratory of Power Transmission Equipment Security, School of Electrical Engineering, North China Electric Power University, Baoding 071003, China.
Polymers (Basel). 2022 Mar 30;14(7):1403. doi: 10.3390/polym14071403.
With the application of the composite cross-arm in power systems, comprehensive anti-aging performance is a key factor to determine whether it can operate safely. In order to study the influence of the operating environment on the external insulation characteristics of composite cross-arms of distribution networks, various aging conditions such as voltage, rain, temperature, humidity, salt fog and ultraviolet light were simulated in a climate chamber based on the real operation conditions of the 10-kV composite cross-arm. A multi-factor aging test of composite cross-arms with two kinds of cross-section shapes (T-shaped and square) was carried out for 5000 h. The change trends of leakage current and flashover voltage of the composite cross-arms before and after aging were analyzed. Finally, the aging mechanism of the silicone rubber sheaths was analyzed to further explain the reasons for the change of external insulation performance of composite cross-arms. The results show that the leakage current rising rate of T-shaped and square composite cross-arms after aging increases significantly, and the minimum flashover voltage decreases to 58.3 kV and 49.502 kV, respectively. The results of FTIR, SEM and hydrophobic angle tests show that, after aging, the performance of the silicone rubber outer sheath material decreases in varying degrees. In general, UV aging has the greatest influence on the external insulation characteristics of composite cross arms. Generally speaking, after 5000 h of multi factor aging, although the external insulation characteristics of the 10-kV composite cross-arm decreases to a certain extent, there is still enough margin to meet the normal operation.
随着复合横担在电力系统中的应用，综合抗老化性能是决定其能否安全运行的关键因素。为研究运行环境对配电网复合横担外绝缘特性的影响，基于10kV复合横担实际运行工况，在气候试验箱中模拟了电压、雨水、温度、湿度、盐雾及紫外线等各种老化条件。对两种截面形状（T形和方形）的复合横担进行了5000h的多因素老化试验，分析了老化前后复合横担泄漏电流和闪络电压的变化趋势。最后，对硅橡胶护套的老化机理进行了分析，以进一步解释复合横担外绝缘性能变化的原因。结果表明，老化后T形和方形复合横担的泄漏电流上升率显著增加，最小闪络电压分别降至58.3kV和49.502kV。傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和憎水角测试结果表明，老化后硅橡胶外护套材料性能有不同程度下降。总体而言，紫外线老化对复合横担外绝缘特性影响最大。一般来说，经过5000h多因素老化后，10kV复合横担外绝缘特性虽有一定程度下降，但仍有足够裕度满足正常运行要求。
