Yläjohtosähköistys

Yläjohtosähköistys, also known as overhead electrification or overhead line electrification, refers to the system of delivering electrical power to a moving vehicle, typically a train or tram, through a system of overhead wires. This system is a common method for powering electric traction. The essential components include the overhead catenary wire, which carries the electrical current, and a pantograph or trolley pole mounted on the vehicle. The pantograph is a device that slides along the catenary wire, maintaining electrical contact and drawing power to the vehicle's motors.

The overhead wires are suspended above the track by support structures, such as poles or gantries. The catenary system is designed to keep the contact wire at a relatively constant height and tension, ensuring smooth and reliable power collection. Different voltage levels and current types, such as direct current (DC) or alternating current (AC), can be used in overhead electrification systems, depending on the application and regional standards.

Overhead electrification offers several advantages, including efficient energy transfer, reduced emissions at the point of use, and quieter operation compared to diesel-powered vehicles. It is widely implemented in urban public transport systems, long-distance railways, and freight lines worldwide. The design and maintenance of overhead lines are crucial for the safe and efficient operation of electric rail transport.