The zinc oxide lightning arrester tester under UHV power can help many power workers conduct various power tests more conveniently.
Zinc oxide lightning arrester is a widely used equipment below 1000kV.
It is a common lightning protection device mainly used to prevent damage to electrical equipment in substations caused by lightning waves. It not only has the best nonlinear volt ampere characteristics, but also has low cost, no gap, no freewheeling, high current carrying capacity, and stable performance. However, sometimes accidents such as malfunctions and explosions may occur.
The common cause of malfunction is mainly due to poor sealing.
Reason analysis: Poor sealing of zinc oxide lightning arrester is mainly caused during the production process of the product. For example, the valve plate of the zinc oxide lightning arrester is not completely dry and contains moisture. Or during the assembly process, the sealing gasket of the lightning arrester may be placed improperly or even not installed. Some manufacturers use substandard materials. For example, the quality of the porcelain bottle used is poor, with invisible holes that can allow moisture to seep in and make the interior damp.
Preventive measures: To prevent poor sealing of lightning arresters, users should conduct strict sealing tests before use. In addition, during the operation and maintenance of zinc oxide lightning arresters, especially after thunderstorms, it is necessary to strengthen the inspection of lightning arresters in order to detect abnormalities in a timely manner. When using a zinc oxide lightning arrester tester for regular preventive testing of lightning arresters, testers must carefully analyze the test data. When the lightning arrester is damp, there may not be any problems with its appearance, but internal defects can only be discovered through test data.
Reason 2: Internal valve plate aging
Cause analysis: Valve aging generally occurs during operation. Due to the poor uniformity of the lightning arrester valve plate and varying degrees of aging, the potential distribution of the valve plate will be uneven. After running for a period of time, some valve discs deteriorate first, resulting in increased leakage current and power loss of the lightning arrester.
Due to the constant voltage of the power grid, the burden on the other normal valves in the zinc oxide lightning arrester is heavy, resulting in rapid aging. This creates a vicious cycle, ultimately leading to internal breakdown of zinc oxide lightning arresters, single-phase grounding, or explosion accidents of the lightning arrester body.
Another reason for the accelerated aging of zinc oxide lightning arrester valves is that the zinc oxide lightning arrester continues to operate under low voltage. This will lead to a significant increase in the load of the zinc oxide lightning arrester during operation, especially when the system is single-phase grounded, causing rapid aging of the valve plate.
Preventive measures: In response to the aging problem of zinc oxide lightning arresters, in addition to requiring manufacturers to improve production processes and increase valve uniformity, lightning arresters with sufficient rated voltage and continuous operating voltage must also be selected during design and selection. In addition, during the inspection, not only should the appearance of the lightning arrester be checked for damage and flashover, but the leakage current value of the lightning arrester should also be replicated and compared with the initial value. If the value is too large, defects should be reported and dealt with in a timely manner.
