Analysis and Protection Studies of Bird Droppings Falling on the Electric Field Distribution Near the 330-kV Transmission Line V-Type Composite Insulators

Recently, the number of birds along the 330kV transmission lines in the northwest region has gradually increased. The frequency of birds nesting and excreting on the towers has been steadily rising, with bird droppings increasingly becoming the primary factor causing bird-related tripping faults. A three-dimensional model of the tower cross arm, continuous bird droppings, and insulators was constructed to simulate and analyze the impact characteristics of bird droplet diameter, length, and relative position to insulators on the spatial electric field near the insulators. Experimental corrections were made, and based on simulation and experimental results, a bird-proof baffle was designed. Research results indicate that under conditions of single-ended grounding and suspended droplets of bird droppings, the average electric field strength at the lower end of the bird droppings and the grading ring was extracted to define the protective area against irregular-shaped bird droppings. After experimental validation, a correction coefficient of 1.4 was obtained based on the experimental results. A square protective baffle with a diversion function was designed based on simulation and experimental results. Bird droppings were placed at the baffle's diversion groove, and the average electric field strength between the lower end of the bird droppings and the grading ring was consistently lower than the breakdown field strength of 2.98 kV/cm. The research results of this paper can serve as a basis for the subsequent designing of physical models of bird-proof baffles and prevention of bird-related flashover faults on V-type insulators.