Influence of glucose as a contaminant on discharge characteristics of HVAC insulator
Influence of glucose as a contaminant on discharge characteristics of HVAC insulator
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DOI：
10.1109/tdei.2015.005177
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发表时间：
2016-03
影响因子：
3.1
通讯作者：
Shuai Yang;Wenjun Zhou;Jianhui Yu;Chengke Zhou;Hui Hu;Baoshan Wang;Cuiru Yang
中科院分区：
文献类型：
--
作者：
Shuai Yang;Wenjun Zhou;Jianhui Yu;Chengke Zhou;Hui Hu;Baoshan Wang;Cuiru Yang
污染物是影响绝缘性能的主要因素。污秽成分决定了绝缘放电的起始电压和放电强度。本文研究了交流500 kV钢城变电站低湿度（77%RH）下污染物含有葡萄糖的强烈放电活动，而这一现象在以前的出版物中很少得到解释。通过放电试验（低于80%RH）、人工污秽试验（100%RH）、分子动力学模拟和量子化学计算，研究了葡萄糖作为绝缘表面污染物的电学和化学性能。实验结果表明，由于葡萄糖的吸湿能力较强，当葡萄糖含量超过0.10 mg/cm 2时，在75%RH下，葡萄糖污染样品的放电起始电压较低，放电强度较强。量子化学计算表明，在强电场作用下，葡萄糖分子可以分解产生带有未成对电子的自由基。表面碳化提高了电子转移速率，增强了放电强度。此外，葡萄糖和水分子的竞争吸附导致低水分排放现象，在制糖地区的保温设计和维护中需要考虑。
Contaminant is the main factor affecting the insulation performance. The contaminant composition determines the inception voltage and the intensity of insulation discharge. This paper studies the intense discharge activity at low humidity (77% RH) in AC 500 kV Gangcheng substation where the contaminant contained glucose, and this phenomenon was rarely explained in previous publications. Electrical and chemical performances of glucose as a contaminant on insulation surface were investigated by means of discharge test (below 80% RH), artificial pollution test (100% RH), molecular dynamics simulations, and quantum chemistry calculations. The experimental results show that due to stronger moisture absorption capacity compared to non-glucose contaminant, glucose contamination sample has lower discharge inception voltage and stronger discharge intensity at 75% RH as the content of glucose exceeds 0.10 mg/cm2. Quantum chemical calculations reveal that the glucose molecules can decompose to generate free radicals with the unpaired electrons under the strong electric fields. The surface carbonation enhances the electron transfer rate and strengthens the discharge intensity. Moreover, the competitive adsorption of glucose and water molecules cause the low moisture discharge phenomenon, and it needs to be considered for insulation design and maintenance in areas producing sugar.