Composite insulators are different from porcelain and glass insulators. The biggest problem with composite insulators is the aging of materials. Electric fields, climate, environmental conditions, mechanical loads, etc. are all important aging factors.
The electric field is determined by the material, length and geometry of the insulator. In order to reduce the electric field around the end attachment, the current composite insulator of 230kV and above is a voltage equalizing ring. In dry climatic conditions, the end field does not produce corona discharge, but if the insulator is fouled. The rain, dew and fog will make the pollution layer wet and conduct electricity, causing leakage current. The leakage current causes the conductive layer to dry (form a drying zone) to arc, resulting in high temperature and high electric field. This arc discharge is not eliminated, and its discharge intensity and duration are closely related to the material of the shed, the climate and the degree of contamination.
Composite insulators may exhibit discoloration, powdering and cracking after several years of outdoor exposure, which is caused by chemical changes in the surface material of the insulator due to the degree of discharge, ultraviolet radiation, and contamination deposition. This deterioration also exacerbates the frequency of discharge. In terms of mechanical strength, it is generally believed that the material used for the mandrel has a tendency to creep, and the mechanical strength of the composite insulator subjected to load tends to decrease over time, depending on the magnitude and duration of the load.
In order to improve the life of composite insulators, in addition to design and process manufacturing levels, the choice of materials is critical. The key to designing composite insulators is to reduce the frequency of surface discharge caused by contamination.
ADDRESS:No.61, Huli Industrial Park,
Meixi Road, Xike Town, Tongan District, Xiamen, China
Please fill in your mailbox information