外部环境因素对MOA在线监测影响的试验

Experimental Study of Influence of Environmental Conditions on On-line Monitoring Data of Metal Oxide Surge Arrester

为研究因环境因素所引起的MOA表面泄漏电流的变化对MOA在线监测结果的影响,通过模拟试验获取了MOA在不同环境条件下的主要绝缘特征参数,进而分析了外部环境因素对MOA在线监测的影响规律。试验结果表明:温度对MOA在线监测结果影响很大,当温度从10°C增加到120°C时全电流几乎增加了一倍,温度对于阻性电流、阻性电流基波分量、阻性电流三次谐波分量以及功率损耗在线监测值变化的影响更大;对于污秽较重的地区,相对湿度对MOA在线监测结果影响同样很大,相对湿度增加时导致泄漏电流增加(主要是阻性电流基波分量,约增加了几十倍),且相对湿度较大时所得的泄漏电流中存在脉冲放电现象,因此,如果直接用测量值和规程规定值作比较是不合适的,需要同时考虑这些环境因素对MOA在线监测结果的影响,从而能对MOA的绝缘状况作出正确的判断。

In order to research the influence of the leakage current that flows through the surface of MOA on the online monitoring data of MOA which is caused by the environmental conditions, the authors simulated the different environmental conditions in the laboratory and gained the main characteristic parameters under these different conditions, and with these data the authors analyzed the influencing rules of the different environmental conditions on the on-line monitoring data of MOA, the experimental results showed that the different environmental conditions would affect the on-line monitoring data of MOA, for example, when the temperature increases from 10 ℃ to 120 ℃, the total leakage current at 120 ℃ is almost as twice as that when temperature is 10 ℃, and the influences of tempera ture on the resistive current, basic component of resistive current, thrice component of resistive current and power loss are more remarkable. In the heavy polluted area, the influence of humidity on the on-line monitoring data of MOA is obvious too. From the experimental results, the main increased component of the leakage current is basic component of resistive current, it increased several decades when the humidity is 10%, and when the humidity increases, it will exist the discharge pulses in the leakage current. So it is not appropriate to compare the on-line monitoring data of MOA with the criterion directly, the influences of these environmental conditions on on-line monitoring data of MOA should be considered and the status of MOA could be estimated correctly.