Overhead traveling trolley
Traction trolley cars are powered by the current supplied to the overhead lines by the traction converter, which enters the circuit and the motor of the trolley car, and then returns to the converter via the track. In China, the DC voltage for underground overhead power grids is either 250V or 550V, while for outdoor grids, it is either 550V or 750V.
1 Benefits: The overhead trolley motor has a simple structure, low cost, easy maintenance, high transportation capacity, high speed, high energy efficiency, low transportation costs, and wide application.
2 Drawbacks: Requires rectification and wiring facilities, lacks flexibility; wiring can affect tunnel dimensions and pedestrian safety; arcing between the pantograph and wiring is common, making it unsuitable for mines with severe gas risks; initial construction investment is high, but in the long run, the total cost of using trolley locomotives with wiring is significantly lower than that of battery-powered locomotives. Therefore, if the mine conditions permit, the main transportation in the mine should use trolley locomotives.
Electric locomotives are a type of traction equipment for rail vehicle transportation. They utilize traction motors to drive wheel rotation, and with the friction between the wheels and the rail surface, the locomotive operates on 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 surface. The gradient capability of the locomotive transportation is limited; the general gradient of the transport tracks is typically 3‰, with local gradients not exceeding 30‰. Structurally, they are categorized into overhead wire types
Track-mounted motor car
The operation process of overhead line locomotives involves high-voltage AC power being stepped down and rectified by the traction converter. The positive pole is connected to the overhead wire, while the negative pole is connected to the rail. The locomotive's collector arm contacts the overhead wire, introducing the current into the train. It then passes through the air automatic switch, controller, and resistor box to the traction motor, driving the motor to operate. The motor, through a transmission device, rotates the wheels, thus pulling the train. The current exiting the motor returns to the converter via the rail.
