Electric Locomotive

Overview

An electric locomotive draws power from an overhead line and uses it to drive traction motors, with no onboard fuel or prime mover. This mainline machine takes 25 kV AC through a roof pantograph, steps it down in a main transformer, and feeds IGBT converters that drive four traction motors. The major systems are the Underframe and Carbody structures, the Pantograph and HV Roof Equipment power intake, the Main Transformer, two Traction Converter units, an Auxiliary Converter, two Bogie running gears, the Air Brake System, the Train Control System control, and the Cab Equipment. Two 12 V Battery units, four Sander Unit adhesion units, and four Headlight lamps complete it.

Structure

The Underframe is a welded Underframe Weldment that carries body and traction loads, fitted with two Automatic Coupler knuckle couplers and four Side Buffer side buffers. The Carbody is a self-supporting Body Shell with two Cab Shell driving cabs at each end.

Power intake

The Pantograph is a single-arm collector whose two Carbon Contact Strip carbon strips ride the contact wire; an Pantograph Arm raises and lowers it from a set of Base Insulator standoffs. From there current passes through the HV Roof Equipment equipment: an Vacuum Circuit Breaker vacuum breaker that can isolate the loco from the catenary, an Surge Arrester clamping voltage spikes, an HV Roof Busbar busbar, and six HV Roof Insulator supports.

Transformer and converters

The Main Transformer steps 25 kV down to converter-feed voltages. A laminated Transformer Core carries six Copper Winding windings in an oil-filled Transformer Tank, cooled by two Oil Radiator coolers and two Blower Motor fans. Each Traction Converter is a liquid-cooled cabinet: twenty IGBT Power Module switches with ten Gate Driver Board drivers rectify the transformer feed to a DC link held by six DC-Link Capacitor capacitors, then invert it to variable-frequency three-phase for the motors, all in an Converter Cabinet. The Auxiliary Converter supplies the three-phase auxiliaries and charges the battery.

Bogies and running gear

Each Bogie is a welded Bogie Frame carrying two Traction Motor motors, two Gear Unit final drives, two Wheelset wheelsets, six Suspension Spring springs, and two Disc Brake Unit disc brakes. Each Traction Motor is a three-phase asynchronous machine with a Stator Assembly and Rotor Assembly on Ball Bearing supports. A Wheelset presses two Monobloc Wheel monobloc wheels onto a shared Axle, and the Disc Brake Unit clamps a Brake Disc with a Brake Caliper.

Brakes and control

The Air Brake System is pneumatic. An Air Compressor charges two Air Reservoir tanks, and two Brake Control Valve valves distribute air to the brake cylinders. The Train Control System ties the locomotive together: an Loco Computer central unit, two LCD Panel driver displays, an ETCS Onboard Unit signaling computer, and a Wire Bundle of control cabling with sixty Connector points and twenty-four Relay units.

Cab and adhesion

The Cab Equipment fits out each cab with two Seat Assembly seats, a Master Controller throttle and brake handle, an LCD Panel desk display, and a Cab HVAC Unit climate unit. To keep the wheels gripping in poor conditions, four Sander Unit units drop sand at the wheel-rail contact, and the Headlight lamps light the line ahead at both ends.