ELECTRIC TRACTION ELECTRIC TRACTION SYSTEMSSYSTEMS

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.)

W B.G.

Y M.G.

Z N.G.

A AC Traction

D Diesel-Electric

Traction (Not DC Traction)

P Passenger

G Goods

M Mixed (Passenger and Goods)

S Shunting

TYPES OF RAILWAY SERVICES Main line service City service or urban service Sub-urban service

  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 GAUGES USED

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

Horn

Pantograph arm

Contact strips

Fig: Pantograph and its parts

OVERHEAD LINE CATENARY

TYPES OF OVERHEAD CATENARY

CONTROLOF

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

BRAKINGOF

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 ???