Study on Fast Contamination Characteristics of Cap and Pin Insulators in Straight Flow Wind Tunnel Simulation

Artificial simulation of rapid insulator contamination can obtain the contamination characteristics of suspension insulators in a short time, providing important reference for the electrical design, operation and maintenance of external insulation. To obtain the contamination characteristics of insulators closer to those under the natural environment, this paper proposed a test method for artificial simulation of rapid natural contamination of insulators using the characteristic parameters of straight-flow wind tunnel, and carried out the artificial rapid natural contamination test of cap and pin insulators under different wind speeds, wind directions, contamination duration and contaminant concentrations. The test results showed that with the wind speed increasing from 2.2 m/s to 7.5 m/s, the contamination degree of insulator surface gradually increased firstly and then decreased, and reached the maximum near 4.5 m/s. With the increase in contaminant concentration, the contamination degree of insulator surface increased, and tended to be saturated when the dust spreading speed was 54 g/min. With the extension of contamination duration, the contaminant accumulation on insulator surface was slow in the initial stage, accelerated in the middle stage, and then slowed down and gradually saturated in the later stage. Under the same contamination conditions, standard, double-shed and triple-shed insulators presented high-to-low equivalent salt deposit density (ESDD) successively on their top and bottom surfaces, and the ratios of ESDD on the top and bottom surfaces were 1:1.20:0.9 and 1:0.63:0.53, respectively.