Why is the lightning arrester the "invisible guardian" of the power system?
Publish Time: 2025-05-27
In modern power systems, various electrical equipment and transmission and distribution lines form a large and complex network. However, behind this seemingly stable operation, there is a threat that cannot be ignored - lightning. Lightning strikes may not only cause instantaneous high voltage, but also damage power equipment, line tripping, and even large-scale power outages. In this context, the lightning arrester, as an important protection device in the power system, silently plays a key role, so it is called the "invisible guardian" of the power system.
1. The hazards of lightning and the vulnerability of the power system
Lightning is a natural phenomenon that generates extremely large instantaneous energy. The current of a direct lightning strike can reach tens of thousands of amperes or even higher. When lightning strikes transmission lines or substation equipment, it will cause extremely high overvoltage, far exceeding the insulation bearing capacity of the equipment, causing damage to transformers, switchgear, cables and other equipment. In addition, even if it is not a direct lightning strike, the electromagnetic pulses generated by lightning induction will interfere with or even damage electronic equipment.
A large number of high-voltage and ultra-high-voltage equipment are used in power systems, and they are extremely sensitive to voltage fluctuations. Once a lightning strike occurs, it will not only have a wide impact range and high repair costs, but may also bring serious economic losses and social impacts. Therefore, how to effectively prevent lightning hazards has become an important issue to ensure the safe and stable operation of the power system.
2. The mechanism of action of lightning arrester: silent guarding, taking precautions
The core function of lightning arrester is to quickly introduce overvoltage into the ground when lightning or operational overvoltage occurs, thereby protecting electrical equipment from damage. It is usually installed near transmission lines, substations and various electrical equipment, like a silent guard, always monitoring voltage changes.
When the voltage exceeds the set safety threshold, the nonlinear resistance element (such as metal oxide varistor) inside the lightning arrester will quickly turn on and discharge the excess current to the ground; at normal voltage, it will return to a high impedance state and consume almost no energy. This automatic response mechanism enables it to complete the protection action within milliseconds to prevent equipment from being damaged by overvoltage.
3. Why is lightning arrester called an "invisible guardian"?
The reason why the lightning arrester is called the "invisible guardian" is that its existence is often not noticed by people, but it plays an irreplaceable role at critical moments:
Silent and continuous protection: The lightning arrester can work for a long time without human intervention and can maintain stable performance even in severe weather conditions.
Prevention is the priority, reducing losses: It prevents the expansion of faults by releasing lightning energy in advance, avoiding damage to expensive equipment and long power outages.
Widely used and indispensable: From urban power grids to remote mountainous areas, from wind turbines to data centers, lightning arresters are almost everywhere in all power facilities and are one of the most important protection devices in the power system.
Although the lightning arrester is small in size, it plays a vital role in the power system. It stands up when lightning strikes and silently guards during daily operations. It is a key line of defense to ensure the safe, stable and efficient operation of the power system. For this reason, it is known as the "invisible guardian" of the power system.
