how sub station works

1. SUB-STATIONS

2. INTRODUCTION
 The assembly of apparatus used to change
some characteristic (e.g. Voltage, a.c to d.c,
frequency, power factor etc) of electric supply is
called a sub-station
The word grid means combination. Combination or
interconnection of various power system elements
such as generating stations, transmission lines,
distribution lines.
Substation is a place where transmission and
distribution lines are connected together.

4. 1. CHANGE VOLTAGE FROM ONE LEVEL TO ANOTHER.
2. REGULATE VOLTAGE TO COMPENSATE FOR SYSTEM VOLTAGE CHANGES.
3. SWITCH TRANSMISSION AND DISTRIBUTION CIRCUITS INTO AND OUT
OF THE GRID SYSTEM.
4. MEASURE ELECTRIC POWER QUALITIES FLOWING IN THE CIRCUITS.
5. PROTECT THE SYSTEM FROM DAMAGE DURING FAULT
Substation Functions

5. 1. TRANSFORMATION
2. REGULATION
3. SWITCHING
4. METERING
5. PROTECTION
Substation Functions

6. CLASSIFICATION OF SUB-STATIONS
Sub-stations
Service
requirement
Constructional
features
Configuration
T/F Sub-
station
Frequency
Sub-station
Switching
Sub-station
Power
factor
Sub-station
Converting
Sub-station
Indoor
Sub-station
Outdoor
Sub-station
Air
insulated
Sub-station
(AIS)
Gas
Insulated
Sub-station
(GIS)

7. INDOOR SUB-STATION

8. OUTDOOR SUB-STATION

9. Air Insulated Electrical Power Substation (AIS)

10. Gas Insulated Electrical Power Substation (GIS)

11. Substation Equipment
• Transformers
• Bus bar
• Circuit breakers
• Isolators
• Earth switches
• Current transformers
• Voltage transformers
• Lightening arresters
• Substation Earthing System
• Shunt reactors
• Wave Trap
• Sub-Station Batteries