1. SWITCHGEAR(220 kV Sub-station, Ablowal) (Patiala) By: Sunpreet Kaur(Lecturer,EE deptt)

2. Overview Key diagram of 220 KV Sub station, Ablowal Cables
Power transformer
Lightening arrester
Circuit breaker
Isolator
Capacitor banks
Earthing
Wave trap

3. Key diagram of 220 kV Sub-station, Ablowal

4. Cables

5. Power transformer 1. Copper loss
Principle of Operation: Mutual inductance
Losses in Transformer
1. Copper loss
2. Core loss
Hysteresis loss
Eddy current loss

6. Power transformer 220/66kV at Ablowal

7. Specification of the power transformer
Manufactured by ABB
Voltage Ratio- 220/66 kV
Class OF/AF Transformer
Rating MVA

8. Lightening Arrester (Thyrite type)
Thyrite type lightening
arrester consists of:
Series spark gap
Non-linear resistor disc in series
(These discs are of 15 cm
diameter and 19 mm
thickness)

9. Lightening Arrester installed at each phase at 220 kV Sub station, Ablowal

10. Circuit breaker Vacuum circuit breaker Arc quenching medium- Vacuum
Voltage range kV
Breaking capacity MVA
SF6 Circuit breaker
Arc quenching medium-SF6 gas at 5 kg/cm2 pressure
Voltage range kV
Breaking capacity ,000 MVA

11. ISOLATOR
Isolators are employed only for isolating circuit when the current has already been interrupted.
They operate under no load conditions and are employed on both the sides of the circuit breaker.
Isolator consists of insulator posts mounted on a support.
There are fixed and moving contacts each made of aluminium.

12. Capacitor bank

13. EARTHING: In sub-station it is necessary to make provision for earthing of neutral points, frames of all equipments and other metal works. Earthing can be divided into two parts:
Equipment earthing:
Equipment earthing deals with earthing of non-current carrying parts of the equipment to ensure safety of personnel and protection against lightening.
Neutral earthing:
Neutral earthing deals with the earthing of the system neutral to ensure system security and protection.

14. Earthing at 220 Kv Sub station, Ablowal
The earthing system consists of an array of conductors buried horizontally at the depth of 0.5 m. such earthing is called an earthing grid or earth mat.
The main steps in the design of the earthing grid are as under:
1. Selection of material and size of the conductor of the grid.
2. Arrangement of the grid conductors.
3. Connection to the grid.

15. WAVE TRAP
It is the effort to utilize the same transmission line between two substations for the purpose of communication.
It does the trapping of high frequency communication signals.
It is relevant in PLCC system for communication among various sub stations.
The wave trap offers high impedance to the high frequency communication signals.

16. Wave trap installed at 220 kV Sub-station, Ablowal

17. SCADA system

18. SLDC (State Load Dispatch Center)
To ensure integrated operation of the power system in the state
Monitoring and control of system parameters.
SLDC keep accounts of the quantity of power transmitted through state grid.
Exercising supervision and control over the intra-state transmission system.
Analysis of tripping/disturbances and facilitating immediate remedial measures.

19. SCADA (Supervisory Control and Data Acquisition System)
Objectives of SCADA system are:
To get real time data from remote locations.
To monitor supply during wide voltage and frequency fluctuations.
To control power load from generating stations and other sub stations.
To monitor PSTCL share in centrally owned power projects.

20. Components of SCADA system
Transducers
PT and CT
RTU
MODEM
PLCC
LAN
Main Server
Wave trap

21. Types of Displays
Oneline Display
Tabular Display

22. Oneline Display

23. Tabular Displays

24. Historical Data Recording

26. Utilities used by SCADA system
Tagging
Trending
Alarm

27. Tagging

28. Trending
The purpose of trending is to reconstruct the post status of SCADA data.
GRAPHICAL DISPLAY of DATA.
One should select the point for trending and define sampling rate and scale values.
It shows us how the different parameters behave in the system.

29. Thank you!!