High-voltage electrical products Outdoor lightning arrester: "Lightning Guardian" of power system

In high-voltage power system, outdoor lightning arrester is a vital protection device, which can effectively prevent lightning overvoltage and operation overvoltage from damaging electrical equipment and ensure the safe operation of power system.

1. Working principle of outdoor lightning arrester

The core function of outdoor lightning arrester is to quickly conduct under overvoltage conditions through its special structure and materials, and safely discharge lightning energy into the earth, thereby protecting electrical equipment from overvoltage shock. Take metal oxide lightning arrester as an example, it is mainly composed of zinc oxide resistor. Under normal operating voltage, zinc oxide resistor presents a high resistance state, allowing only a small leakage current to pass; while under overvoltage conditions, the resistance value of the resistor will drop sharply, forming a low resistance state, thereby quickly discharging the current generated by overvoltage.

2. Classification of outdoor lightning arresters

1. **Gapless metal oxide lightning arrester**: This is the most widely used type of outdoor lightning arrester. It does not have a traditional spark gap, but directly realizes overvoltage protection through the nonlinear characteristics of zinc oxide resistors. This type of arrester has the advantages of good protection characteristics, strong current capacity, low residual voltage and small size.
2. **Series gap type metal oxide arrester**: This type of arrester has a gap in series between the zinc oxide resistor and the external circuit. It is suitable for neutral point non-effective grounding systems and can provide reliable protection under single-phase grounding faults or arc grounding overvoltage.
3. **Tube arrester**: The tubular arrester consists of an inner gap and an outer gap. Its arc extinguishing tube can produce gas at high temperature to help extinguish the arc. This type of arrester is usually used outdoors, especially in situations where rapid arc extinguishing is required.

3. Application scenarios of outdoor arresters

Outdoor arresters are widely used in high-voltage transmission lines, substations, power plants and various outdoor electrical equipment. Their main function is to protect equipment from damage caused by lightning overvoltage and operating overvoltage. For example, in high-voltage transmission lines, arresters can be installed on poles to prevent lightning from directly hitting the wires; in substations, arresters can be installed near key equipment such as transformers and busbars to provide additional protection.

2. Installation and maintenance of outdoor lightning arresters

1. **Installation**: The installation location of the outdoor lightning arrester should be as close as possible to the protected equipment to ensure timely response in the event of overvoltage. At the same time, the grounding system of the lightning arrester must be reliable, and the grounding resistance should meet the relevant standards.
2. **Maintenance**: Regularly check the appearance of the lightning arrester to ensure that there is no damage or aging. In addition, electrical performance tests, such as measuring insulation resistance and leakage current, are required to be performed regularly to ensure the normal operation of the lightning arrester.

5. Future development trends

With the development of the power system, outdoor lightning arresters are also constantly upgrading. In the future, lightning arresters will be more intelligent, able to monitor their own status in real time, and issue early warnings before a fault occurs. In addition, the application of new materials will further improve the performance and reliability of lightning arresters.

As an important protective device in the power system, the role of outdoor lightning arresters cannot be underestimated. By reasonably selecting and installing lightning arresters, the damage to electrical equipment caused by lightning overvoltage can be effectively reduced, and the safe and stable operation of the power system can be guaranteed.