Study on the flashover characteristics of bird droppings along 110kV composite insulator

With the rapid increase of the number of birds, frequent bird droppings flashovers occur in high-voltage power transmission and transformation projects. In order to reduce bird damage and improve the reliability of power system, it is necessary to study the bird droppings flashover in laboratory. Due to the length and the shape of bird droppings is not easy to control, a cotton strip impregnated with the bird droppings simulating liquid was used to simulate bird droppings in this experiment. During the test, the relationship between the spatial position and the corona onset voltage and breakdown voltage was studied when the bird droppings fell from directly above and to the side of the grading ring. Studies have shown that when the distance between the bird droppings simulation strip and the grading ring is getting larger and larger, the breakdown voltage is getting higher and higher. The breakdown field strength gradually decreases as the gap distance increases, the value is close to the breakdown electric field strength with the rod-rod gap.