The Gangshan Lujhu Extension line's Electric Multiple Unit (EMU) system is supplied by Hyundai Rotem. It is in the early stages of design, and the same marshaling method as the original EMU along the Red Line and the Orange Line are adopted. Two powered cars (DM) and one trailer (T) make up a three-car train in the marshaling model, which is referred to as the "marshaling of DM-T-DM" (as shown in Figure 1).

The primary drive and power equipment for the EMU, such as the current collecting equipment, propulsion equipment, auxiliary power equipment and air compressor equipment, are housed in the area under the car floor (as shown in Figure 2 and Figure 3).

The functions of the electromechanical equipment under the car are as follows:

• Current Collecting Equipment

  A car’s power is sourced from the third rail of the collector shoes on both sides of each bogie in contact with the rail, supplying 750V DC power to the propulsion equipment and auxiliary power equipment.

• Propulsion Equipment

  The primary propulsion equipment under the car includes a traction converter box, a line circuit breaker box, a filter inductor, a mode switch box, a traction motor, and other devices.

  The traction converter converts the 750V DC third-rail power received from the current collecting equipment into 380V AC power for use by the traction motor. Each power car is equipped with four traction motors for acceleration and electric regenerative braking.

• Auxiliary Power Equipment

  Auxiliary power equipment consists of static converters, battery chargers, batteries and battery boxes, among other components. Each car is outfitted with two sets of auxiliary power equipment installed in the trailer, and the two sets can serve as each other's backup.

  Auxiliary power equipment converts 750V DC power into AC 380V and DC 110V power to power car air conditioners, control power supplies, lighting equipment, air compressors, and other devices.

• Air Compressor Equipment

  The primary air compressor equipment installed on the vehicle's undercarriage consists of air compressors, air storage tanks, and so on.

  Each power car is equipped with a set of air compressors that can supply the compressed air necessary for the operation of the friction brake equipment and other pneumatic auxiliary vehicle components (such as the secondary suspension, collector shoes, etc).