Fault Prevention And Control Of High Voltage Isolating Switch

The causes of the above-mentioned hv isolator switch defects or failures include manufacturing process, material quality problems, and some are caused by improper inspection and maintenance. To ensure the safe operation of high voltage electrical isolator, ensuring its initial quality is the key.
Strengthen selection
It is necessary to collect the operation conditions of isolator high voltage in the system and select products with reasonable structure, excellent design and high overall quality.
Technical transformation
1. The problem of porcelain bottle breakage must be comprehensively managed. First of all, the overall structure of the disconnector must be ensured to be reasonable. Secondly, the selection of porcelain bottle manufacturers must be strengthened. The disconnector manufacturer can be specified to use products of porcelain bottle manufacturers with excellent quality and good reputation. In addition, non-destructive testing technology can be carried out to regularly inspect porcelain bottles. Operators should strengthen monitoring, especially the observation of the glued surface of porcelain bottles. The method should be appropriate during operation. If there are difficulties in operation, do not force the operation.
2. The heating of the conductive circuit of the disconnector and the flashover of the porcelain bottle seriously affect the safe operation of the equipment. The static contact finger compression spring can be replaced with a stainless steel spring, and stainless steel bolts or hot-dip galvanized high-strength bolts can be used and tightened with a torque wrench; adjust the contact insertion depth and clean the contact surface, or use self-cleaning contacts similar to Siemens. At the same time, infrared temperature measurement technology is used to regularly detect the heating of the conductive parts, and problems are dealt with in a timely manner.
The flashover of the porcelain bottle is mainly caused by serious dirt accumulation on the surface of the porcelain bottle and the inside of the porcelain skirt, and the small creepage distance of the porcelain skirt. Especially for the knife switch in the heavily polluted area, chemical pollution and cement fouling not only make the cleaning of the porcelain bottle extremely difficult, but also the presence of a large amount of industrial dust and corrosive gases in the air can easily cause flashover discharge of the porcelain bottle, expanding the scope of the accident. In 2001, the 110kV knife switch of Pengchang transformer located in the chemical industry zone in the northern suburbs of Xuzhou had a large-area flashover discharge of the porcelain bottle, causing the porcelain bottle to burst. In response to this situation, live cleaning can be adopted to strengthen the cleaning intensity, silicone rubber umbrella skirts can be added to the porcelain bottle of the disconnector to increase the creepage distance, and RTV can be sprayed using the hydrophobicity of RTV coating.
3. Rust is the primary problem that affects the safe and reliable operation of the disconnector. Anti-rust treatment is carried out regularly, and lubricants are added to each transmission part, especially molybdenum disulfide lubricants whose performance is better than butter. The brass sleeve is replaced with a composite sleeve with sintered bronze on the steel base and modified polytetrafluoroethylene, and the outer surface and ends are tinned to prevent rust. The mechanism box is made of high-quality stainless steel products, the disconnector base is modified, holes are drilled on the base, and molybdenum disulfide is added regularly during operation to ensure that the bearings do not rust.