What type of power supply is predominantly used in modern electrified rail networks?

The predominantly used power supply in modern electrified rail networks is high voltage three-phase AC or DC. This is due to several key advantages that these systems provide for rail transportation.

High voltage three-phase AC is particularly effective in transmitting large amounts of power over long distances with minimal losses due to resistance. This is essential for rail systems that require a reliable and efficient power supply to maintain operational efficiency, especially for high-speed trains and heavy freight operations. The use of three-phase AC allows for a more stable and balanced power distribution, which is crucial for the smooth functioning of electric traction systems.

Additionally, many rail networks are also adopting high voltage DC systems, which offer rapid energy transfer and have become popular in urban transit and certain high-speed rail applications. These systems are beneficial because they can be implemented with simpler traction equipment and have advantages in terms of control and regenerative braking.

Overall, the choice of high voltage systems—whether AC or DC—supports the high power demands of modern trains while ensuring efficiency and reliability, making it the preferred solution for electrified rail networks today.