Special Challenges of Lightning Arrester in DC Transmission System and Technological Innovations to Address Them?
Publish Time: 2024-12-03
In the field of modern power transmission, DC transmission system plays an increasingly important role. As a key device to ensure the safe and stable operation of DC transmission system, lightning arrester faces many special challenges.
In DC transmission system, lightning arrester needs to deal with long-term DC voltage stress. Unlike AC system, DC voltage does not have a zero crossing point, which makes the internal resistor of lightning arrester continuously under high electric field when it is subjected to DC voltage, making it more prone to thermal breakdown and aging. For example, the materials and structures of traditional lightning arrester may increase leakage current under such long-term DC stress, thus affecting its protection performance.
At the same time, the switching overvoltage and lightning overvoltage in DC system have unique waveforms and characteristics. The rising rate and duration of the switching overvoltage are different from those in AC system, which requires lightning arrester to have more precise action response characteristics, and be able to start protection action at the appropriate voltage threshold and time point to effectively limit the overvoltage amplitude and prevent equipment insulation damage.
To meet these challenges, a series of technological innovations have emerged. In terms of materials, new resistor materials with higher tolerance to DC electric fields, lower leakage current and better thermal stability have been developed. These materials can maintain stable performance under long-term DC voltage by optimizing the formula and manufacturing process, reducing the risk of aging and damage.
In terms of structural design, a multi-column parallel structure lightning arrester is adopted to increase the current capacity and better cope with the large energy overvoltage shock that may occur in the DC system. In addition, by improving the heat dissipation design of the lightning arrester, such as adding heat sinks or using special heat dissipation channels, the temperature of the resistor during operation is effectively reduced, further enhancing its long-term operation reliability.
In addition, intelligent monitoring and diagnosis technology is also widely used in DC lightning arresters. By online monitoring of the leakage current, number of actions, temperature and other parameters of the lightning arrester, using big data analysis and artificial intelligence algorithms, the real-time evaluation of the status of the lightning arrester and fault prediction can be achieved, so that timely maintenance and replacement can be carried out to ensure the safe and stable operation of the DC transmission system.
In short, with the continuous development of DC transmission systems, lightning arrester has been continuously innovating in technology in the process of responding to special challenges, with breakthroughs in many aspects from materials, structures to monitoring technologies, which has safeguarded the reliable operation of DC transmission networks and promoted the power industry to move towards a more efficient and stable direction.
