ELECTRIC TRACTION SYSTEMS Prepared By :

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

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.

TRACTION SYSTEM, ITS CLASSIFICATION AND NOMENCLATURE

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

NOMENCLATURE IN INDIAN RAILWAYS Name 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.

TYPES OF RAILWAY SERVICES TYPES 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

SYSTEMS OF TRACK ELECTRI-FICATION Direct 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

POWER SUPPLY IN ELECTRIC TRACTION (AC AND DC SYSTEMS)

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

OVERHEAD LINE CATENARY

TYPES OF OVERHEAD CATENARY

CONTROL OF TRACTION MOTORS

CONTROL OF DC TRACTION MOTORS Rheostatic Control Series-Parallel Control

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

CONTROL OF AC INDUCTION MOTOR Rheostatic Control Pole-Changing Control Cascade Control Combination of Cascading and Pole-Changing Control

BRAKING OF TRACTION MOTORS

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

REGENERATIVE BRAKING

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

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