1 ELECTRIC TRACTION SYSTEMSPrepared By :

2 MOTIVATION Sheer size and roaring sound.Use of electronics to bring down distance and time. A fascination for electrical students - Use of traction motors - Speed Control - Braking

3 TOPICS TO BE DISCUSSED Traction system, its classification and nomenclature. Power Supply in Electric Traction (AC and DC systems). Traction motors used. Control of traction motors. Braking.

4 TRACTION SYSTEM, ITS CLASSIFICATION AND NOMENCLATURE

5 INTRODUCTION Traction - locomotion on the rails (driving force - steam or electric drive) Classification of Traction Systems: > Non-Electric > Electric - receive electricity externally - self contained locomotives

6 NOMENCLATURE IN INDIAN RAILWAYSName consists of four parts e.g. WDP2: Diesel-Electric Passenger train running on broad gauge W/Y/Z (Gauge type) A/D (Mode of traction) P/G/M/S (What for it is used) 2/4/6/2C (Model No.) A  AC Traction D  Diesel-Electric Traction (Not DC Traction) P  Passenger G  Goods M Mixed (Passenger and Goods) S  Shunting W  B.G. Y  M.G. Z  N.G.

7 TYPES OF RAILWAY SERVICESTYPES OF GAUGES USED Type of Gauge Gauge Width 1. Standard Gauge or Broad Gauge (B.G) 1.676 m 2. Meter Gauge (M.G) 1.0 m 3. Narrow Gauge (N.G) 0.762 m 4. Light Gauge (L.G) 0.610 m TYPES OF RAILWAY SERVICES Main line service City service or urban service Sub-urban service

8 SYSTEMS OF TRACK ELECTRI-FICATIONDirect current system Single phase low frequency a.c system Single phase high frequency a.c system Three phase a.c system Composite system - Single phase to Three phase - Single Phase to Direct Current

9 POWER SUPPLY IN ELECTRIC TRACTION (AC AND DC SYSTEMS)

10 POWER SUPPLY IN ELECTRIC TRACTIONConductor Rail System Overhead System Contact strips Horn Pantograph arm Fig: Pantograph and its parts

11 OVERHEAD LINE CATENARY

12 TYPES OF OVERHEAD CATENARY

13 CONTROL OF TRACTION MOTORS

14 CONTROL OF DC TRACTION MOTORSRheostatic Control Series-Parallel Control

15 CONTROL OF DC TRACTION MOTORS (Contd.)Field Weakening Method Diesel-Electric Locomotive Control

16 CONTROL OF AC INDUCTION MOTORRheostatic Control Pole-Changing Control Cascade Control Combination of Cascading and Pole-Changing Control

17 BRAKING OF TRACTION MOTORS

18 BRAKING Electrical Braking - Plugging - Rheostatic Braking- Regenerative Braking Mechanical Braking - Compressed Air Brake - Vacuum Brake - Magnetic Track Brake

19 REGENERATIVE BRAKING

20 ADVANCED TRACTION SYSTEMSMultiple Unit Traction System (EMU, DMU) Driving force – from multiple units EMU – suburban railway transport Rheostatic Control

21 ANY QUESTIONS ??? CONCLUSIONAdvanced technologies – Magnetic Levitation used for ultra high speed trains Electric traction – economical, easy and safe ANY QUESTIONS ???