The residual voltage and impulse discharge voltage of the lightning arrester are key indicators of its protection effect, and play a vital role in the lightning protection of electrical equipment.
Residual voltage refers to the voltage value that appears at both ends of the lightning arrester when it is subjected to lightning overvoltage. The magnitude of the residual voltage directly reflects the voltage bearing capacity of the lightning arrester under lightning impulse. If the residual voltage is too high, it means that the lightning arrester may generate a large leakage current under the action of lightning overvoltage, which will not only consume the energy of the lightning arrester, but also may cause damage to the lightning arrester itself. In addition, excessive leakage current may also cause secondary harm to surrounding equipment, such as causing insulation breakdown or damage to the equipment, thereby reducing the lightning protection effect. Therefore, residual voltage is one of the important indicators for evaluating the protection performance of the lightning arrester. The lower the residual voltage, the better the protection performance of the lightning arrester is generally.
Impulse discharge voltage is one of the key indicators of the performance of the lightning arrester. It refers to the voltage value at which the lightning arrester begins to conduct electricity under the action of lightning impulse. When the lightning overvoltage exceeds this value, the lightning arrester will quickly operate and introduce the lightning current into the ground, thereby protecting the electrical equipment from damage. The level of the impulse discharge voltage directly affects the protection effect of the lightning arrester. If the impulse discharge voltage is set too high, the lightning arrester may not operate in time under the action of the lightning overvoltage, thus failing to effectively protect the electrical equipment. On the contrary, if the impulse discharge voltage is set too low, it may cause the lightning arrester to malfunction under normal operating voltage, affecting the normal operation of the power system. Therefore, a reasonable impulse discharge voltage setting can ensure that the lightning arrester operates in time and accurately under the action of the lightning overvoltage, introduces the lightning current into the ground, thereby protecting the electrical equipment and personal safety.
There is a certain relationship between the residual voltage and the impulse discharge voltage. Generally speaking, the lower the impulse discharge voltage, the lower the voltage value at which the lightning arrester starts to conduct electricity under the lightning impulse, which means that the lightning arrester can respond to the lightning overvoltage earlier and play a role. However, too low an impulse discharge voltage may also cause the lightning arrester to malfunction under normal operating voltage. The residual voltage is the voltage value that still exists at both ends of the lightning arrester after it is actuated. Therefore, when selecting a lightning arrester, it is necessary to comprehensively consider the two parameters of impulse discharge voltage and residual voltage to ensure that the lightning arrester can be actuated in time under the action of lightning overvoltage and maintain a low residual voltage level after actuation.
The magnitude of residual voltage and impulse discharge voltage is affected by many factors, including the structure and material of the lightning arrester itself, the installation environment, and the strength of the lightning overvoltage. For example, metal oxide lightning arrester (MOA) can quickly reduce voltage and limit current under the action of lightning overvoltage due to its nonlinear resistance characteristics, thus having a lower residual voltage and higher impulse discharge voltage tolerance. However, silicon carbide lightning arrester may produce higher residual voltage and leakage current under the action of lightning overvoltage due to its relatively poor resistance characteristics.
In order to optimize the protection effect of the lightning arrester, the following aspects can be taken into consideration: First, select the appropriate type and specification of the lightning arrester, and make comprehensive considerations based on the system's voltage level, the frequency of lightning activity, and the installation environment; second, strengthen the maintenance and inspection of the lightning arrester, and promptly discover and deal with potential faults and problems; third, improve the installation environment of the lightning arrester, such as improving the reliability and stability of the grounding system; fourth, adopt advanced lightning protection technology and equipment, such as installing auxiliary equipment such as surge protectors to further improve the lightning protection capability of the system.
In actual applications, the compatibility of the lightning arrester with other electrical equipment and the overall lightning protection plan of the system also need to be considered. For example, when selecting a lightning arrester, its ability to work in conjunction with other electrical equipment such as transformers and switchgear, as well as the compatibility evaluation method, need to be considered. At the same time, it is also necessary to formulate a suitable lightning protection plan based on the overall lightning protection needs of the system, including the layout and quantity of the lightning arrester and its coordination with other lightning protection equipment.
The residual voltage and impulse discharge voltage of the lightning arrester are one of the key indicators of its protection effect. The protection effect of the lightning arrester can be optimized and the lightning protection capability of the system can be improved by properly selecting the type and specification of the lightning arrester, strengthening maintenance and inspection, improving the installation environment, and adopting advanced lightning protection technology and equipment. At the same time, in actual applications, it is also necessary to consider the compatibility of the lightning arrester with other electrical equipment and the overall lightning protection solution of the system to ensure the safe and stable operation of the system.
