181 / 2018-08-26 21:26:53

Experimental analysis of characteristics of saturation pollution on high voltage insulator in North China

Pollution,Particle Size,composition,Outdoor Insulators

The pollution on the surface of high voltage insulator including a composite insulator, ceramic insulator and glass insulator may lead to the pollution flashover of electrical outdoor insulation, thus, the characteristics of pollution on the surface of high voltage insulator deserve detail investigated. In the present work, the characteristics of saturation pollution on high voltage insulator in North China were analyzed in terms of pollution particle size analysis, pollution particle morphology and chemical component analysis. In general, the natural pollution after four years of accumulation can be considered as the saturation pollution, therefore, the pollution particle attached on composite insulator, ceramic insulator and glass insulator were collected after more than four years of natural accumulation in North China, then, the experimental results in present work can reflect the characteristics of saturation pollution. Firstly, the equivalent salt deposit density (ESDD) was measured according to the IEC 60815, the results showed that the ESDD for composite insulator was larger than the ESDD for ceramic and glass insulators. Secondly, the particle size analysis showed that the distributions of pollution particle size on ceramic and glass insulators were almost the same, however, the distribution of pollution particle size on composite insulator was quite different from the former two, more specifically, the pollution particle with lager size can be observed on the surface of composite insulator. Based on the experimental analysis results of the pollution collected from the high voltage insulator, it can be concluded that the interaction between the pollution and the bulk of the high voltage insulator was a key process affecting the performance of pollution, the unique ability of diffusion of LMW from bulk to surface endow the pollution with hydrophobicity and adsorption force resulting in the formation of cluster of pollution. Based on the microscopy observation, it can be found that the pollution particle on composite insulator has two kinds of aggregate appearance, that is, the cluster of particle and the isolated particle, while the pollution particle on the ceramic insulator and glass insulator only have one form, that it, the isolated particle. Moreover, it should be noted that due to the diffusion of LMW and the interaction between the LMW and pollution, the ESDD on composite insulator was larger and the particle size on composite insulator was alas larger than that on ceramic insulator and glass insulator, therefore, the evaluation on the pollution performance of high voltage insulator should be more comprehensive. The present study is a case study of the pollution and is helpful for better understanding of the pollution characteristics on high voltage insulator used in North China.