You can know the summary of the Bangladesh power system in FY 2020-21 also know the substation equipment.

1. Discussion on Sub-Station Equipment
and Power Grid System in Bangladesh

2. Structure of Power Sector
Energy and Mineral
Resources Division
Ministry of Power, Energy and Mineral
Resources
BERC Power Division
Power Cell
BPDB

3. About BPDB
Bangladesh Power Development Board (BPDB) is a statutory body established on May 31, 1972 by Presidential Order No. 59
after bifurcation of erstwhile Bangladesh Water and Power Development Authority. BPDB had started its operation with
generation capacity of only 500 MW. In its 49 years’ service, the installed capacity of the country increased to 22,031 MW
(Installed capacity 25,235 MW including captive & off-grid renewable energy) at the end of the FY 2020-2021.
BPDB
Generation Transmission Distribution
APSCL
EGCB
NWPGCL
IPP
PGCB DPDC
DESCO
REB
NESCO

4. Power Grid System
 An electric grid is a network of synchronized power providers and consumers that are
connected by transmission and distribution lines and operated by one or more control
centers.
Bangladesh’s national grid covers the entire country and operates at 132 kV, 230 kV, and
400 kV. The country’s transmission system is connected to the national grid of India
through 400 kV lines at Bheramara and Cumilla.
Why is the Electric Power Grid Important?

5. Grid Infrastructure

6. Generation Overview

7. Installed Capacity
Total installed capacity was 22,031 MW, which includes 10,146 MW Public, 1,244 MW JV, 8,141 MW IPP/SIPP, 1,089 MW
Rental Power Plant, 251 MW under REB (for PBS) and 1,160 MW power import from India. The maximum peak generation
was 13,792 MW, which was 8.27% higher than the previous year.

8. Install Capacity, Maximum Forecasted Demand & Maximum Demand Served
Load Curve

9. Power Grid Company of Bangladesh (PGCB) is solely responsible for Operation, Maintenance and Development of the
transmission system of the Country for distribution of generated electricity. The main operating function of PGCB is wheeling of
energy from BPDB power stations and Generation Companies to Distribution entities utilizing transmission network. PGCB gets
its energy wheeling charge from its clients (distribution entities) at the rate fixed by Bangladesh Electricity Regulatory
Commission (BERC).
Transmission

10. Primary Grid System

11. Distribution
BPDB has been functioning as a retail seller of electricity within its following four distributions zones:
Distribution zone, Chattogram Distribution zone, Mymensing
Distribution zone, Cumilla Distribution zone, Sylhet
BPDB has extended about 1,595 numbers. distribution transformer with 358 MVA capacity as a part of continuous
improvement of the system. BPDB covers electrification in 204 thanas/upazillas and 6,470 villages within its four distribution
zones.
Distribution Network Summary Distribution Commercial Summary
Single Line Diagram

12. Control System in Distribution side
BPDB has engaged Consultants to implement Supervisory Control And Data Acquisition (SCADA) system in its four
distribution zones for system control and data acquisition of the distribution system/networks under it from one point of each
zone through microwave link. BPDB also has a plan to set up one SCADA in Dhaka to monitor/control all SCADA of BPDB
centrally.
SCADA is the acronym
for Supervisory Control
and Data Acquisition.
SCADA is a computer-
based system for
gathering and analyzing
real-time data to monitor
and control equipment
that deals with critical and
time-sensitive materials or
events.
What is SCADA? Why do BPDB need SCADA?
 Supervising/Monitoring the
networks.
 Data acquisition and recording of
power flow/supply status of the
entire networks on hourly basis.
 Preparing and reporting daily and
monthly power supply, demand,
load shedding, line shut-down.
 Load management matching with
the power generation as per
instructions of NLDC

13. Demand Side Management
Demand Side Management (DSM) means modifying energy use to maximize energy
efficiency.
 DSM tries to get maximum benefit out of existing energy generation.
 DSM involves changing energy use habits of consumers and encouraging them for using
energy efficient appliances, equipment etc. at their premises.
Demand Side Management
Energy Efficiency Demand Response
Reliability Based
Market Based

14. Future context of Bangladesh in power sector
The Government has set up a goal of providing electricity to all by 2021 and to ensure reliable and quality supply of electricity
at a reasonable and affordable price. Renewable Energy based projects can help Bangladesh to meet its policy goals for secure,
reliable and affordable energy access to people. BPDB has taken systematic steps to implement renewable energy-based
projects and to promote Energy Efficiency Measures from the year 2009 to achieve the policy target.
Projects under
Planning
Owner
ship
Place
Construction of 109.77
MWp (82.5 MW AC)
Solar Photovoltaic Grid
Connected Power Plant.
BPDB Sonagazi,
Feni
Construction of 90.25
MWp (68.60 MW AC)
Solar Photovoltaic Grid-
Connected Power Plant.
BPDB Gangachara,
Rangpur.
Renewable
Energy based
power plant
IPP Projects under
Planning
Owner
ship
Place
200 MW (AC) Grid Tied
Solar PV Power Project by
Beximco Power Company
Ltd & TBEA Xin Jiang Sun
Oasis Co.Ltd .
IPP Sundarganj,
Gaibandha
100 MW (AC) Solar Park by
a Consortium of Energon
Technologies FZE, UAE
and China Sunergy Co. Ltd.
(CSUN).
IPP Bora Durgapur,
Mongla,
Bagerhat

15. Future Distribution Projects
From the view point of continuous improvement in retail sales performance and consumers’ service & satisfaction, BPDB
has undertaken following distribution projects-
BPDB planned to import 500 MW power from Nepal by 2026. To strengthen
transmission and distribution system, plans are being prepared to construct additional
5,346 ckt km transmission line 46,604 MVA capacity-based grid sub-station, 85 thousand
km new distribution line and related distribution substation by 2025.

16. Contents
Introduction
A Short History of Substation
Classification of Substation
Substation Layout
Substation Equipments
Lighting arresters
CVT
Wave Trap

17. Introduction
 A substation is a part of an electrical generation , transmission and distribution where the voltage is
transformed from high to low and low to high for transmission, distribution, transformation and switching.
 The power transformer, circuit breaker, bus bar, insulator, light arrester are the main components of an
electrical substation.
Substation

18. Short History
 Electricity generation is the process of generating electric power from other sources of
primary energy. The fundamentals behind electricity generation were discovered around
1830s by Michael Faraday.
 In the past electricity was only utilized where it was generated.
 But the demand of power increased even from those areas where generation is not
possible. To overcome these limitations the establishment of substations were necessary.
 In 1901 Nawab of Dhaka installed a small generation in Ahsan Monjil on 7th December.
 East Pakistan Water and Power Development Authority was established to look after
generation, transmission and distribution.
 After independence of Bangladesh in 1972 Bangladesh Power Develpoment Board
(BPDB) was created to look after the same functions.

19. Step up substation:
It is also known as
primary substation and
normally it is situated near
generation station.
Step down substation:
It is also known as
distribution substation
and normally it is situated
near load.

24. Substation Layout

25. Substaion Equipment
Some other important component is CVT and Wave trap

26. Lightening Arrester

27. CVT

29. Instrument Transformer

30. Instrument
Transformer
Current
Transformer
(C.T)
Potential
Transformer
(P.T)
Classification of Instrument Transformer

31. Current Transformer (C.T)

32. Current Transformer
Why the secondary winding of current transformer is always shorted?
Connection Scheme

33. Potential Transformer (P.T)

34. Potential Transformer (P.T)
Potential Transformer (P.T)
Connection Scheme

35. Bus Bar

36. Types of Bus Bar arrangement
 Single Bus Bar.
 Single Bus Bar with Bus Sectionalized.
 Main and Transfer Type.
 Double Bus Bar Double Breaker.
 Sectionalized Type Arrangement.
 One and Half Breaker.
 Ring Arrangement.
 Mesh Arrangement.

37. Bus Bar Arrangement

39. Circuit Breaker
 A circuit breaker is an automatically operated
electrical switch designed to protect an electrical
circuit from damage caused by an overloading or
short circuit.
 Its basic function is to interrupt current flow to
protect equipment and to prevent the risk of fire.

40. Types of Circuit Breakers
There are different types of circuit
breakers used for any substations. They
are-
a. SF6 circuit breakers.
b. Oil circuit breakers.
c. Spring circuit breakers.
d. Vacuum circuit breakers.

41. Circuit Breakers

42. Power Transformer
 A power transformer is a static machine used for transforming power from one
circuit to another without changing the frequency.
 In case of a 220kv or more kv line station auto transformers are used. While in case
of lower kv line such as less than 132kv line double winding transformers are used.

43. Types of Power Transformer
 There are different types of power transformer.
a.Step up transforner.
b.Step down transformer.
Other types of power transformer-
1.three phase transformer.
2.single phase transformer.

44. Isolator
 The isolators in substations are mechanical switches
which are deployed for isolation of circuits when there
is an interruption of current.
 The use of this isolators is to protect the transformer
and the other instrument in the line.
 To disconnect part of the system for general
maintenance and repairs.
 Operated only when lines carry no current.

45. Types of Isolator
 There are different types of isolators-
a. Single break isolator.
b. Double break isolator.
c. Pantograph isolator.
d. MCB isolator.

46. Control & Relay
Jahangir alam

47. Relay
A relay is an electrically operated SWITCH
A Relay is a automatic device which sense an abnormal condition of Electrical
Circuit and closes its contacts. These contacts in turns close and complete
and Circuit Breaker trip coil circuit hence make the circuit breaker tripped
for disconnecting the faulty portion of the electrical ckt from rest of the
healthy circuit.

48. Connection Scheme

49. Classification of Protective Relays
1. Depending on the technology
Electromagnetic relays: coil, moving parts mechanical
Static Relays: semiconductor devices; thyristors
µP based relays:
2. Based on function:
Overcurrent
Undervoltage
Impedance relay
Underfrequency
Directional relays
3. Construction
Electromechanical
Solid State
Microprocessor
Numerical

54. Undervoltage
A relay that has contacts that operate when the voltage drops below a set voltage.
Undervoltage relays are used for protection against voltage drops, to detect short-circuit
faults, etc.
Underfrequency

56. Control
Jahangir alam

59. Control panels contain meters, control switches and recorders located in
the control building, also called a doghouse. These are used to control the
substation equipment, to send power from one circuit to another or to
open or shut down circuits when needed.
Here the operator can view the alarms, breaker states, measures of
power elements (transformers, generators, loads, etc). Depending on all
the information that the operator receives, he will operate the
incomings, the tie breakers, the outputs for the loads or simply will
phisically check the elements that are generating an alarm before a
major fault occurs.

60. Substation Control Systems ( SCS)
The substation control system is complete system by which all the events,
measurements operation and control of the substation is achieved from the local
PC as well as the Remote control center.

61. 1.
2.
3.
4.
5.
6.

62. 7.
8.
9.
10
11.
12.

63. 20
.
17
.
16
.
15
.
14
.
13
.
19
.
18
.

64. 1. Setting the Relay from the Local PC as well as the Remote Control center
2. Viewing the different events in the relay like operation of a an element of a relay ,
Starting of an element of a relay etc.
3. Disturbance viewing of the relays
4. Giving different alarms and the status of the Relay itself
5. Recording the events like operation of CB isolator etc. with time stamp
6. Control of the CB and Isolators from the local PC as well as the Remote Pc
7. Operation of the On load tap changers of the Power transformers
8. measurement of current voltage , frequency. Active Power reactive Power etc. of each
feeders and Transformers
9. Other information's like transformer monitoring system etc. can be sent to the control
center
10 All other substation alarms and events general in nature like temperature , Fire
systems and so on
The main application of the SCS

65. DC power supplies for substations are an absolute requirement. The DC supply is used in every type of control
that is required in substations from powering the battery banks to providing a consistent supply to any form of
powered system.
DC Power Supply

66. Main components of DC supply system
 Battery Bank
 Charger
 DCDB

67. Associated System in Sub-Station
• Substation earthing system
• Overhead earth wire shielding or lighting masts
• Illumination system (lighting)
• Protection system
• Control cable
• Power cable
• PLCC system
• Auxiliary standby power system
• Fire fighting system