The main differences between AC cable and DC cable lie in their application systems, transmission efficiency, power loss, safety, structural complexity, and cost.
Different application systems: AC cable are mainly used in power systems with a frequency of 50Hz in China, while DC cable are used in rectified DC transmission systems.
Transmission efficiency and energy loss: The energy loss of DC cable during transmission is relatively small, mainly because their energy loss is mainly due to the DC resistance loss of the conductor, while the insulation loss is relatively small; For example, photovoltaic cable are typical DC cable. In contrast, AC cables experience significant energy loss during transmission, especially Medium Voltage Cable, where insulation resistance losses account for a large proportion due to proximity and skin effects.
Safety: The use of DC cable is relatively safe because they are difficult to generate induced and leakage currents, and do not interfere with the electric fields generated by other cables. In addition, single core cable laying will not affect the transmission performance of the cable due to hysteresis loss of the steel structure bridge.
Structure and Cost: The structure of DC cable is relatively simple, usually consisting of positive and negative poles, while AC cable use a three-phase four wire or five wire system with high insulation safety requirements and complex structure. Therefore, the cost of AC cable is usually more than three times that of DC cable.
Installation and maintenance: The installation and maintenance of DC cable are relatively simple and cost-effective, while the installation and maintenance of AC cable are more complex and costly.
In summary, DC cable have advantages in transmission efficiency, safety, cost, and installation and maintenance, while AC cable are suitable for traditional power frequency systems, each with its own application scenarios and advantages.
