First, introduce the composite insulator, commonly known as porcelain insulator, which is used to support the conductor. It can ensure that the conductor, cross arm and tower have sufficient insulation. The manufacturing technology of composite insulator is mature, the strength and process of mandrel are simple, and the matching design of hardware strength and crimping strength is reasonable. During long-term operation in high humidity atmosphere, if the hydrophobicity of composite insulator is partially or completely lost, it is easy to cause flashover accident due to arc short circuit between umbrella skirts, which seriously threatens the safe and reliable operation of power grid.
At present, the umbrella skirt shape of composite insulator of transmission line has been greatly improved compared with the past, which is mainly composed of large and small umbrella, three umbrella structure, five umbrella combination, two large and two medium umbrella types. The umbrella diameter reaches 200 mm and the umbrella spacing reaches 140 mm; For all kinds of hollow composite insulators, it is necessary to prevent the dense umbrella skirt structure design from being chained in rainstorm or rainstorm, resulting in rain flash. Therefore, the optimization design of composite insulator umbrella skirt shape is still a focus that needs systematic research. The design of interface and sealing structure is the key to the design of composite hollow insulator. After all, the operation time of composite insulators is short and the number is small. Many key technologies have not been tested by the operation environment for a long time, especially the interface between end accessories, FRP epoxy resin pipe and umbrella cover. If handled improperly, it will affect the safe operation of composite hollow insulators.
Some enhancers are located upstream and some downstream of the promoter, so the effect of composite insulator does not depend on the relative position of composite insulator and promoter. Therefore, the reason for the directionality of composite insulator effect has not been really understood. At present, it has been found that two loci affect the function of composite insulators through trans activation. The nuclear protein encoded by gene S2J (HW) can recognize the composite insulator, and the composite insulator can have insulation effect only when combined with it. Therefore, the composite insulator enhances the insulation effect.
