Elements of power Systems

1. Sub-Station
Made by:--
Swapnil Patel

2. Table of Contents
Introduction about sub-station
Classification of substation
Comparison between indoor and
outdoor substation

3. Introduction about sub-station
The assembly of apparatus used to change some
characteristics of electric supply is called a
sub-station.
• It should be at proper location.
• It should provide safe and reliable
arrangement.
• It should be easily operated and maintained.
• It should involve minimum capital cost.

4. Classification of substation
1. Service requirement
2. Constructional features

5. 1. According to Service requirement
• It which change the voltage level .
(i) Transformer Sub-station
• It perform the switching operations of power lines .
( ii) Switching Sub-station
• It improves power factor .
(iii) Power factor Correction
• It Changes the Supply Frequency.
(iv) Frequency changer
• It Change a.c. power into d.c. power.
(v) Converting Sub - Station
• It supplies power to Industrial Individual concerns.
(vi) Industrial Sub - Station

6. 2. According to Constructional feature
• For Voltages upto 11 kV .
(i) Indoor Sub-station
• For Voltages beyond 66 kV .
( ii) Outdoor Sub-station
• The sub - station is created
underground .
(iii) Underground Sub-station
• This is an outdoor sub - station with equipment
installed over-head on H-pole or 4-pole structure .
(iv) Pole - mounted Sub-station

7. Comparison between indoor and
outdoor sub- station

8. References
• Elements of power systems by V K Mehta.
• Background Photo By SWAPNIL PATEL