As a key device for lightning protection in power systems, the performance changes of lightning arresters under multiple lightning strikes are crucial.
First, during multiple lightning strikes, the performance degradation of lightning arresters shows a certain pattern. With the increase in the number of strikes, key components such as the zinc oxide valve plate inside the lightning arrester will gradually deteriorate. For example, the large current generated by the lightning strike will cause the valve plate to heat up, resulting in changes in its resistance characteristics, and the leakage current may gradually increase. Initially, this change is relatively slow, but after multiple high-intensity lightning strikes, the performance degradation rate will accelerate. At the same time, the discharge voltage of the lightning arrester may gradually decrease, and its ability to limit lightning overvoltage will also be weakened, which may expose the power system to a higher risk of overvoltage and threaten the insulation safety of the equipment.
Secondly, the reasons and internal mechanisms of its performance degradation are explored. On the one hand, the thermal effect under high current strikes is one of the main factors. Each lightning strike will cause the lightning arrester component to generate heat. If the heat cannot be dissipated in time, the accumulated high temperature will destroy the microstructure of the valve plate and change its electrical properties. On the other hand, the electric force caused by the lightning strike will also damage the internal structure of the lightning arrester. Strong electric forces may loosen the connection between valve plates or deform the internal electrodes, further affecting the performance of the lightning arrester.
In addition, regarding the recovery mechanism of the lightning arrester after the impact. When the lightning impact ends, the lightning arrester will have a natural cooling and self-adjustment process. During this process, if the heat dissipation conditions of the lightning arrester are good, its internal temperature will gradually decrease, and some performance changes caused by thermal effects may be restored. For example, some slight resistance changes may gradually return to normal as the temperature decreases. However, for structural damage caused by electric forces, etc., recovery is more difficult and may require professional inspection and repair.
Understanding the performance degradation law and recovery mechanism of the lightning arrester after multiple lightning impacts is of great significance to the safe and stable operation of the power system. Power operation and maintenance personnel can formulate reasonable inspection cycles and maintenance strategies based on these laws, timely detect changes in the performance of the lightning arrester and take corresponding measures, such as replacing degraded lightning arresters or improving their heat dissipation environment, to ensure that they continue to play an effective role in lightning protection and protect the power system from the serious impact of lightning disasters.
