Electric locomotives are traction devices used for rail vehicle transport, powered by drive motors that rotate the wheels. They utilize the friction between the wheels and the rail surface to propel the locomotive along the tracks. This mode of operation is limited by both the power of the traction motor (or internal combustion engine) and the friction between the wheels and the rail. The transport capacity of locomotives is restricted by the gradient they can travel, with typical track gradients at 3‰ and local gradients not exceeding 30‰. They are categorized structurally into overhead cable locomotives and battery-powered locomotives.

Battery-powered electric trolley

The working principle of battery-powered locomotives is similar to that of overhead-catenary locomotives. Direct current supplied by the battery is driven through explosion-proof plug connectors, controllers, resistor boxes, and other components to operate the motor, thereby propelling the train.

Battery-powered rail vehicle

Battery-powered electric locomotives are powered by batteries. Battery charging typically occurs in the underground electric locomotive garage. Once the battery pack on the locomotive reaches a certain level, it is removed and replaced with a fully charged one. Therefore, each locomotive must be equipped with 2-3 battery packs.

Advantages: No spark ignition hazard, suitable for use in mines with gas; no need for wiring, flexible usage, highly applicable for small output and irregular tunnel transportation systems as well as tunnel excavation transportation.

Drawbacks: Requires charging equipment; high initial investment; low energy efficiency; higher transportation costs.