Three Phase Technology PDF

3. POWER CIRCUIT DESCRIPTION (Refer Fig. 3.1 & Fig. 3.2 ) The locomotives WAP5 and WAG9 are having 3-phase drive with GTO thyristors and microprocessor based control system. The primary winding of the main transformer is fed from the OHE (25 kV, single phase ac...

3. POWER CIRCUIT DESCRIPTION (Refer Fig. 3.1 & Fig. 3.2 ) The locomotives WAP5 and WAG9 are having 3-phase drive with GTO thyristors and microprocessor based control system. The primary winding of the main transformer is fed from the OHE (25 kV, single phase ac, 50 Hz) through the pantograph (1) and the vacuum circuit breaker (5). Two surge arrestors (9/1 & 9/2) are provided on the roof – one at the pantograph end and the other after the VCB. A primary voltage transformer (6.1) is provided at the primary side of the main transformer (7) to monitor the overhead catenary voltage. Signal from this primary voltage transformer is continuously monitored by the control electronics. In addition to serving other control functions, this signal is used by the control electronics to protect the equipment on the locomotive by tripping off the VCB in case of catenary voltage going out of limits. The main transformer is a specially built high impedance transformer as compared to those used in conventional locomotives. In addition to the primary winding, there are four traction windings and one auxiliary winding. A harmonic filter winding is also provided which has a filter connected across it to reduce the harmonics. In case of WAP5 loco, one hotel load winding is additionally provided. Each group of two traction windings feed two 4-quadrant line converters (12/1 & 12/2) connected in parallel. The line converters feed an intermediate circuit (known as DC link) consisting of a series resonant circuit (15.3, 15.4) and DC link capacitors (15.5), which supply power to the drive converter (12/3 + 13/1). The drive converter feeds two traction motors of a bogie in case of WAP5 and three traction motors of a bogie in case of WAG9. The traction motors are instantaneously discharged through the MUB resistor. Firing of the GTOs is controlled by the control electronics. During regenerative braking, the traction motors are made to act as induction generators by controlling the output frequency to obtain a negative slip value. In the line converter, the resultant 3-phase electrical energy is converted into single-phase energy through the DC link and is fed back to the catenary via the main transformer. The fundamental reactive power flow can be adapted to the line voltage conditions independent of the active power flow, thanks to the 4-quadrant pulse controlled converter. Thus the converter also serves to stabilize the line voltage. TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 35 TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 36 TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 37  SALIENT DATA OF MAJOR SUBSYSTEMS OF WAP 5 LOCOMOTIVE EQUIPMENT, TYPE, MAKE AND MAIN RATING / DATA 1.1 Traction motor : Make : ABB Switzerland 4 Nos/loco Type : 6 FXA 7059 Cont. Max. Voltage phase to phase 2180 2180 V Current per phase 370 593 A Frequency 80 160.3 Hz Output at shaft 1150 1150 Kw Torque at shaft 6930 9920 Nm. Speed 1585 3174 rpm. Cos phi 0.86 All the above values are given for half worn wheels Design Speed 3571 rpm Over speed test speed 3571 rpm Stator winding Class 200, Veridur (R) system Insulation system 1.2 Transformer: Make : ABB, Switzerland 1 no / loco Type : LOT 7500 Rating : at 25 kV line voltage Primary winding 25 kV, 7475 kVA, 299 A Traction winding 4x1269V, 4x1449 kVA, 4x1142 A Aux. Converter winding 1000V, 334 kVA, 334 A Hotel load winding 750 V, 945 kVA, 1260 A Filter winding 1154 V, 400 kVA, 347 A No load current 0.5A at 22.5 kV Series resonant circuit 2x984 Arms,2x0.551 mH, Assembled in reactor linear upto 2x1391A peak transformer Cooling system Forced oil cooling Oil type shell using standard Diala DX mineral oil Impedances Traction winding ex = 59.4% (Guaranteed value for er = 3.08 % traction winding inductivity L = 2.1 mH + 15% only, others for information R = 34 m purpose) Aux. Converter winding TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 38  ex = 6.68 % er = 1.01% L = 0.5 mH R = 23.7 m Hotel load winding ex = 19.52 % er = 1.85 % L = 0.37 m R = 11 m Temp. Rises Primary 11 K Traction 17 K Aux. Converter 12 K Hotel load 13 K Filter 3K Temperature Cu. max. 100 C Oil max. 84 C Oil mean 82 C 1.3 Power converter: Make : ABB, Switzerland 2 Nos./ loco Type : UW 2423 – 2810 (i) 4 Quadrant power converter Suitable for Transformer secondary 2 x 1269 V at 25 kV line voltage voltage Frequency 50 Hz + 3% DC link voltage 2800 V nominal Cooling system Forced oil cooling Oil type shell using standard Diala DX mineral oil. (With 8 GTO Thyristors 4.5 kV / 3kA, Toshiba Type SG 3000 GXH 24 or equivalent type and gate units and 8 power Diode type D921S45T Eupec Make or equivalent) (ii) Motor Inverter Suitable for Motor voltage 2180 V (phase to phase) Motor frequency 0…160.3 Hz DC link voltage 2800 V (nominal) Cooling system Forced oil cooling Oil type shell mineral oil. Diala D TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 39  (With 6 GTO Thyristors 4.5 kV / 3kA, Toshiba Type SG 3000GXH24 or equivalent type and gate units and 6 Power Diode Type D921S45T Eupec Make or equivalent) (iii) DC Link Capacitor Make : Condis Type : CDM15230A0815 Rating : Capacity : 815 µF : Voltage :2940 Vnom Bank : 11.41 mF Capacity (iv) Instant Voltage Limitation Make : Microelettrica Scientifica, Italy Type : MUB Voltage : 2800 V Current : 500 A Containing - GTO thyristor and gate units - power diode - power resistor (Microelecttrica) (With 1 GTO Thyristors 4.5 kV / 3kA, Toshiba Type SG 3000 GXH 24 or equivalent type and gate units and power Diode type D921S45T Eupec Make or equivalent) (v) Series Resonant Circuit Capacitor Make : ERO Type : ERO – GFP 3.8 Rating : 560 µF, 2940 V Bank : 4.6 mF (The bank has 8 nos of Capacity these capacitors and one adjustable capacitor unit consists of 3 capacitors (280 µF+140µF+140 µF) TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 40 SALIENT DATA OF MAJOR SUBSYSTEMS OF WAG9 LOCOMOTIVE EQUIPMENT, TYPE, MAKE AND MAIN RATING / DATA 1.1 Traction motor : Make : ABB Switzerland 6 Nos/loco Type : 6 FRA 6068 3-phase Induction Motor Axle hung nose suspended type Cont. Max. Voltage phase to phase 2180 2180 V Current per phase 270 393 A Frequency 65 132 Hz Output at shaft 850 850 Kw Torque at shaft 6330 9200 Nm. Speed 1283 2584 rpm. Cos phi 0.88 All the above values are given for half worn wheels Design Speed 2842 rpm Over speed test speed 3250 rpm for 2 minutes Stator winding Class 200, Veridur (R) system Insulation system 1.2 Transformer: Make : ABB, Switzerland 1 no / loco Type : LOT 6500 Rating : at 25 kV line voltage Primary winding 25 kV, 6531 kVA, 261.25 A Traction winding 4x1269V, 4x1449 kVA, 4x1142 A Aux. Converter winding 1000V, 334 kVA, 334 A Filter winding 1154 V, 400 kVA, 347 A No load current 0.5A at 22.5 kV Series resonant circuit 2x984 Arms, 2x0.551 mH, Assembled in reactor linear upto 2x1391A peak transformer Cooling system Forced oil cooling Oil type shell using standard Diala DX mineral oil Impedances Traction winding ex = 59.4% (Guaranteed value for er = 3.08 % traction winding inductivity L = 2.1 mH + 15% only, others for information R = 34 m purpose.) TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 41  Aux. Converter winding ex = 6.68 % er = 1.01% L = 0.5 mH R = 23.7 m Temp. Rises Primary 11 K Traction 17 K Aux. Converter 12 K Hotel load 13 K Filter 3K Temperature Cu. max. 100C Oil max. 84C Oil mean 82C 1.3 Power converter: (Similar to WAP5 locomotive) TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 42