What is the difference between DC cables and AC cables?
1) They are used in different systems. DC cables are used in rectified DC transmission systems, while AC cables are commonly used in industrial frequency (50 Hz in China) power systems.
2) Compared to AC cables, DC cables offer higher transmission efficiency and lower energy loss during transmission. Due to the inherent characteristics of AC and DC, AC cables have not only core resistance loss, but also insulation loss and magnetic induction loss in the armor. DC cables, on the other hand, have essentially only core resistance loss.
3) DC cables are more convenient than AC cables for regulating current and changing the direction of power transmission.
4) Although converter equipment is more expensive than transformers, the cost of using DC cables is much lower than that of AC cables. DC cables have two positive and negative poles and a simple structure. AC cables are three-phase four-wire or three-phase five-wire systems, with strict insulation safety requirements and a more complex structure. The cost of AC cables is more than three times that of DC cables.
5) DC cables are highly safe to use: 1. The inherent characteristics of DC transmission make it difficult to generate induced currents and leakage currents, resulting in no electric field interference with other cables installed in the same cable. 2. Single-core cables are not affected by hysteresis losses in steel bridge structures, which can affect cable transmission performance. 3. They have higher current carrying capacity and overload protection than AC cables of the same structure. When DC and AC electric fields of the same voltage are applied to the insulation, DC fields are significantly safer than AC fields. 6) DC cables are simple to install and maintain, and are relatively inexpensive.
