TD unit-5 Anna Univeristy

1. UNIT V
SUB-STATION, GROUNDING
AND
DISTRIBUTION

2. SUB-STATION BUS SCHEME
Introduction:
The choice of bus schemes or arrangements depends on relative
important assigned to such things as
• Safety,
• Reliability,
• Voltage Level,
• Simplicity of Relaying,
• Flexibility of Operation,
• Least Cost,
• Ease of Maintenance,
• Available Land,
• Location of Connecting Lines And Provision of Expansion

3. TYPES SUB-STATION BUS SCHEME
1. Single bus scheme and single bus with
sectionalizer
2. Double bus with double breaker
3. Double bus with single breaker
4. Main and transfer bus
5. Ring bus
6. Breaker-and-a-half with two main buses
7. Double bus-bar with bypass isolators

4. 1. Single bus scheme and single
bus with sectionalizer

5. 2. Double bus with double breaker

6. 3. Double bus with single breaker

7. 4.Main and transfer bus

8. 5.Ring bus

9. 6. Breaker-and-a-half with two
main buses

10. 7. Double bus-bar with bypass
isolators

11. Thank You