ELECTRIC TRACTION SYSTEMS Prepared By MOTIVATION Sheer size

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. WDP 2: 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) W B. G. A AC Traction P Passenger Y M. G. D Diesel-Electric G Goods Z N. G. M Mixed Traction (Not DC Traction) Goods) S Shunting 2/4/6/2 C (Model No. ) (Passenger and

TYPES OF GAUGES USED Type of Gauge Width 1. Standard Gauge or Broad Gauge (B. G) 1. 676 m 2. Meter Gauge (M. G) 3. Narrow Gauge (N. G) 4. Light Gauge (L. G) 1. 0 m 0. 762 m 0. 610 m TYPES OF RAILWAY SERVICES Ø Main line service Ø City service or urban service Ø Sub-urban service

SYSTEMS OF TRACK ELECTRI-FICATION Ø Direct current system Ø Single phase low frequency a. c system Ø Single phase high frequency a. c system Ø Three phase a. c system Ø 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

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