Working Principle of Narrow Gauge Trolley Electric Locomotive for Mine

The trolley locomotive receives electric energy from the circuit by pantograph. When the locomotive is running, the pantograph slides along the trolley line.

The power supply mode of the trolley locomotive is that the high voltage cable from the central substation is supplied to the three-phase AC power supply of the traction converter, which is lowered by the transformer and then sent to the converter by the low-voltage cable to convert AC to DC. The positive pole of DC power supply is connected with overhead wire through power supply cable. During the period, the contact becomes the power supply point. The negative pole of DC power supply is connected with track through return cable. The corresponding contact point is called return point.

When working, the upper part of the locomotive running along the track relies on the pantograph contacting the trolley line to obtain electric energy, while the lower part uses the wheel contacting with the track to form a loop to make the traction motor work, so that the locomotive can drive the mine car.

Thus, the running track of the trolley locomotive is also the conductor of the current loop. In order to reduce the voltage drop of traction power grid, conductors or copper sheets are usually used to connect the joints of rails in order to reduce the resistance at the joints.