雾霾天气对复合绝缘子运行性能的影响

Influences of Haze Weather on Operating Performance of Composite Insulators

为探究雾霾天气对电力设备外绝缘的危害,以现场运行的复合绝缘子进行试验研究。雾霾对复合绝缘子的影响主要体现在2个方面:一是导致复合绝缘子表面积污量的增加;二是其产生的湿沉降会增加绝缘子的泄漏电流、降低闪络电压。利用河北省石家庄地区的雾霾天气进行了360 h的自然积污试验,分别在不同的雾霾脏污程度下试验3次,研究污秽度和泄漏电流与雾霾的脏污程度及作用时间之间的关系。试验结果表明:雾霾天气的发生会在短时间内增加绝缘子表面的污秽度,在数十小时内可以使绝缘子表面的等值盐密增加0.01?0.04 mg/cm2、灰密值增加0.05?0.2 mg/cm2;空气质量指数不同,试品表面污秽度增加情况也不同;雾霾日数的增加是影响复合绝缘子表面污秽度的重要因素;雾霾产生的湿沉降会增加复合绝缘子的泄漏电流。短期内雾霾天气不会导致复合绝缘子发生污闪故障,但随着雾霾作用时间的延长和环境污染的加剧,污闪的可能性是存在的。

Taking being operated composite insulators as the object, the exploration on the affects of haze whether on the external insulation of power equipments is performed. The affects of haze on the composite insulator represent in two aspects： A） leading to the increase of the dirt retention on the surface of composite insulators and B） increasing the leakage current and decreasing the flashover voltage of composite insulators due to the wet deposition caused by the dirt retention. A natural deposit contamination test with the duration of 360 hours during the haze weather in Shijiazhuang area of Hebei province is preformed, and the test is repeated three times under different dirt level of haze whether respectively to research the relationship among the pollution degree, the leakage current, the dirt level of the haze and its actuation duration. Test results show that along with the occurrence of haze whether the pollution degree on the composite insulator surface increases in a short time, and within dozens of hours the equivalent salt deposit density（ESDD） on the insulator surface may be increased from 0.01 mg/cm2 to 0.04 mg/cm2and the non soluble deposit density（NSDD） may be increased from 0.05 mg/cm2 to 0.2 mg/cm2; the pollution degree on the surface of the specimen differently increases under different air quality indices; the increase of the haze days is an important factor impacting the surface pollution degree of the composite insulator; the wet deposition caused by the haze may lead to the increase of leakage current of the composite insulator. The haze whether during a short period will not lead to the pollution flashover of composite insulators, however with the extension of the haze days and the aggravation of the environmentpollution, it is possible for the occurrence of the pollution flashover.