DC cables are an important part of the power transmission field and are mainly used for the transmission of electric power. Specifically, DC cables can realise long-distance power transmission, and through the research and development of high-voltage DC cables, China has made remarkable progress in its research and development, production and operation.
Firstly, DC cables are capable of large-scale power transmission. Compared with AC cables, DC cables have a larger transmission capacity and a longer transmission distance, so they are widely used in the fields of wind power grid integration, island power supply and cross-sea long-distance power transmission.
Secondly, DC cables have higher transmission efficiency. Since the current direction of DC cable always remains the same, it will not produce electromagnetic induction and electromagnetic radiation in the transmission process, thus reducing the loss of energy.
In addition, DC cables have better stability. Since the current direction of DC cables always remains the same, there is no electromagnetic induction and electromagnetic radiation during transmission, thus reducing energy loss.
Finally, DC cables have lower maintenance costs. Since the current direction of DC cables always remains the same, there is no electromagnetic induction or electromagnetic radiation during transmission, thus reducing energy loss.
However, DC cables also have some problems during use. For example, the insulation materials of DC cables, unlike AC cables, have the phenomenon of negative temperature coefficient, which reduces the resistance as the temperature rises, which may lead to uneven distribution of electric field stress and easy aging at the smallest point of insulation resistance, affecting the service life.
In general, DC cables play an important role in power transmission, with the advantages of large transmission capacity, long transmission distance, high transmission efficiency and good stability. However, it is also necessary to pay attention to the aging of insulation materials and insulation performance in the process of use to ensure the safety and stability of power transmission.