Jingang Li

The contamination deposition characteristics of insulators can be used in the development of antifouling work. Using COMSOL software, numerical simulations on the pollution-deposited performance of a porcelain three-umbrella insulator and porcelain bell jar insulator in a wind tunnel were conducted, and the simulated results were compared with the tested results. The comparison shows that the deposit amount is consistent with the order of magnitude and presents a similar tendency with Direct Current (DC) voltage variation; then the rationality of the simulation is verified. Based on these results, simulations of the natural contamination deposition on porcelain insulators and the distribution of pollution along the umbrella skirt were performed. The results indicates that, under a same wind speed, contamination of the porcelain three-umbrella insulator and porcelain bell jar insulator under DC voltage was positively correlated with the particle size. With the same particle size, the proportion of the deposit amount under DC voltage (NSDD_DC) to the deposit amount under AC voltage (NSDD_AC) of both insulators decreases with the increase in wind speed. However, the ratio increases as particle size increase. At a small wind speed, the deposit amount along the umbrella skirt of the two insulators displays a U-shaped distribution under DC voltage while there is little difference in the contamination amount of each skirt under Alternating Current (AC) voltage.

The mechanical mechanism of pollution accumulation on XP13-160 porcelain suspension disc insulators was analyzed, and a discriminant for the deposition on the insulator surface was proposed. A simulation of the pollution accumulation characteristics of the insulator in the wind tunnel at North China Electric Power University was conducted through COMSOL Package, and the simulation results were compared with the results from wind tunnel test. The verification results show the rationality of the proposed deposition discriminant and the simulation method. According to these results, a simulation study was conducted on the natural pollution accumulation characteristics of the insulator to analyze the effects of individual and composite factors such as wind speed, particle size, and voltage type. The results show that under natural gentle wind, the overall surface deposit amount increases as the wind speed increases and approximately linearly increases with the particle size. The particle size displays a greater effect on pollution accumulation than the wind speed. Under the AC voltage and the unelectrified state, the overall surface deposit amount does not essentially change at low wind speed and slowly increases at high wind speed with increasing particle size. The proportion of NSDDDC to NSDDAC shows a trend of gradual decrease with increasing wind speed, and the trends are similar under different sizes.

In order to study the contamination characteristics of porcelain suspension disc insulators, forces on polluted particles in a low wind speed condition were analyzed, and using COMSOL, a simulation of the pollution accumulation characteristics of the Porcelain Three Umbrella Insulators was conducted in the wind tunnel at North China Electric Power University, and the simulation results were compared with the results from the wind tunnel test conducted at the campus. The comparative results show that the simulation results and the tested results with respect to the overall surface deposit amount are at the same order of magnitude, and overall, they display a consistent changing pattern with DC voltage variation and a V-shaped distribution, which confirms the rationality of the simulation method. Based on these results, a simulation analysis was conducted on the natural contamination Characteristics of the insulator by this method to analyze the natural contamination distribution rule along umbrella skirt under different wind speed, particle size, particle charges, and voltage type conditions. The results show that under DC condition, the overall surface deposit amount is influenced by the particle charge, and the greater the particle charge, the deposition is higher; the values of the deposition on the upper and lower surface under AC voltage and the unelectrified state are similar in different wind speed and particle sizes, the deposition on the upper is higher than it on lower surface when wind speed at 0.5m/s, the deposition on the upper and lower surface significantly increased when DC voltage was applied or wind speed increased.