A New Evaluation Method of Aging Properties for Silicon Rubber Material Based on Microscopic Images

In recent years, composite insulators have been widely applied in transmission lines; however, deterioration of insulation properties caused by aging may cause power supply's large-scale outage and badly impact the social economy development. Therefore, in this paper, an entirely new method for evaluating aging properties of silicon rubber for composite insulators based on microscopic images was proposed. The microscopic images were collected by portable digital microscope-B011, and defective area proportion (k) was extracted by calculating and comparing the defective area pixel with the background pixel. Thus, the salt fog flashover experiments were conducted in a multifunction artificial climate chamber to indicate aging properties of silicon rubber material; then, the equations for calculating silicone rubber flashover voltage (U-50) by k were established. The value of U-50 can even decrease by 57.3% with the increase in the value of k. Moreover, a complete aging evaluation procedure of silicone rubber composite insulators was obtained. Taking a city as an example, the critical failure k (k1 = 19.6) value of composite insulators in the area was obtained. Finally, the future research directions of this paper were clarified; besides, future usage scenarios of this paper were clearly displayed.