Three-Phase AC Traction Technology for Diesel-Electric Locomotive WDG4 of Indian Railways Te c h n i c a l I n f o r m a t i o n In 1999 Indian Railways introduced its first diesel-electric freight locomotive with three-phase AC traction technology; the WDG4 locomotive. The state-of-the-art AC traction system, consisting of 2 inverters and 6 AC motors, is based on the well-proven Siemens design already in operation on more than 1500 US-locomotives of EMD. Pulse-width modulated (PWM) inverters with GTO thyristors are driving brushless three-phase induction traction motors in axle-hung, nose-suspended design. Traction control by Siemens SIBAS® 16 microcomputers. The microcomputer controlled AC traction system provides: Wheel arrangement Co’Co’ 0-6-6-0 1676 mm 66 in 126 t 278 000 lbs 21 244 mm 836 in 1092 mm 43 in 90 : 17 5.29 : 1 100 km/h 62.5 mph EMD 16-710 G3B 4 000 HP/2985 kW at 900 rpm 3350 HP 2500 kW Starting tractive effort 540 kN 121 400 lbs Continuous tractive effort 400 kN 90 000 lbs Braking effort 270 kN 60 698 lbs Track gauge Weight Length over couplers Wheel diameter Gear ratio Maximum service speed Diesel engine Type Diesel engine Rating Power at wheel • High starting and continuous tractive efforts • Dynamic braking • Effective wheel slip and slide control • Long maintenance intervals • Fault monitoring and diagnostic functions • Overload protection Design of WDG4* Locomotive: Electro-Motive Division of General Motors Corp. (EMD) La Grange, Illinois, USA *Based on GT46MAC locomotive of EMD, USA Manufacturing of WDG4 in India: Diesel Locomotive Works (DLW) Indian Railways, Varanasi, India Development and supply of AC traction equipment: Siemens AG, Germany and Siemens Ltd. India 7 3896 8 640 8 2743 640 19964 6 4, 5 2,3 1 General view 3 3~ 5 = G 3~ 2 1 M 3~ 4 3 6 6 7 7 6 6 = M 3~ 3~ 8 M 3~ 1 Diesel engine 2 Generator 3 Rectifier 4 Traction inverter 5 DC link capacitor 6 Braking contactors 7 Braking resistors 8 Traction motors M 3~ 4 = 3~ 5 = M 3~ 3~ 8 M 3~ Main circuit diagram Tractive and braking effort diagrams High starting and continuous tractive efforts achieved by system optimization of the traction inverter and motors. High dynamic braking capability within a wide speed range. EMD GT46 MAC IR – TE diagram (throttle 8) EMD GT46 MAC IR – BE diagram 600 0 0 20 40 60 80 550 500 –50 braking effort [kN] tractive effort [kN] 450 400 350 300 250 200 –100 –150 –200 150 100 –250 50 0 0 20 40 60 80 speed [km/h] 100 120 140 –300 speed [km/h] 100 120 140 Locomotive and traction control G 3~ Diesel engine Traction inverter Driving Central control unit Braking Diesel engine M 3~ Generator Direction Auxiliaries Diagnostics Multipliunit traction M 3~ Traction inverter M 3~ Traction control unit SIBAS 16 Traction control Slip and slide control Inverter protection Diagnostics Traction control Slip and slide control Inverter protection Diagnostics The Traction Control Cabinet (TCC) contains the traction inverter with control computer and is the three-phase AC power supply for the traction motors of one locomotive truck. A TCC consists of the following main components: • 3 phase modules including gate drive units • 1 DC-link capacitor set • 1 set of current and voltage transformers • 1 snubber resistor • 1 fan • 1 SIBAS® 16 traction control computer • 1 inverter protection circuit Each phase module contains the power semiconductors for one inverter phase (two GTO thyristors 4,5 kV/3,0 kA and two antiparallel diodes) as well as the snubber circuit diodes and capacitors. The GTO gate drive units are mounted outside on the module cover. The heat losses of the electrical components arranged in the module are dissipated by evaporation bath cooling, a method long proven in rail vehicles. The traction control computer is housed in a separate compartment of the traction control cabinet. Doors and latches provided in the cabinet afford easy and direct access to all components. The fan installed in the traction control cabinet draws air across the phase modules. Air is exhausted across the snubber circuit resistor on the opposite side of the cabinet. The electronic components, such as GTO gate drive units, are cooled by means of fine filtered air. They are pressurized to extensively rule out contamination. A noteworthy feature of the design is that the traction control cabinet forms an integral part of the locomotive hood. Technical Data Input Rated current 300 V to 2 600 V DC variable 580 A Output Voltage range 0 V to 2000 V 3-phase AC variable Rated Current 900 A Frequency range M 3~ Traction control unit SIBAS 16 Traction Control Cabinet Nominal voltage range M 3~ 0 Hz to 110 Hz variable M 3~ The control system of the entire locomotive is based on microcomputer technology. It comprises a SIBAS® 16 traction control computer for each inverter and a locomotive control unit. The central locomotive control unit, EM 2000 of EMD, processes the commands from the driver’s desk or trainlines to form the reference values for traction control. SIBAS® 16 traction control computer The inverter for each truck is controlled by a traction control unit SIBAS 16 which contains the microcomputer control, I/O modules, communication module as well as the necessary microcomputer power supplies. The control unit performs such functions as traction control, wheel slip and slide control, inverter protection and diagnostics. Traction motor 1TB2622 Traction motor 1TB2622 is a four pole three-phase induction motor designed to deliver very high torques required for the high starting tractive effort of the locomotive. The motor is of an extreme robust design suitable for challenging operation conditions, e.g. highly dusty environment and vibrations experienced on the tracks. The rotor is of a squirrel-cage design. The stator is a laminated frame construction with no housing. Laminations are held together by sturdy end plates and welded tie-rods. The forcedventilated motor is designed for axle-hung roller-bearing installation. Technical Data Weight 2120 kg Starting torque 9 471 Nm Nominal power 425 kW Nominal insulation voltage 2300 V Nominal speed Maximum speed 600 rpm 3320 rpm The stator winding is insulated according to insulation class 200. Siemens AG Transportation Systems Group Locomotives P.O. Box 32 40 D-91050 Erlangen Siemens Aktiengesellschaft M o b i l i t y for a moving world. Siemens Transportation Systems Reg. No. 2234 Order No. A19100-V600-B434-X-7600 Printed in the Fed. Rep. of Germany 141D6215 174652 DB 9001. Subject to change without prior notice