Wapda internship report

UNIVERSITY OF ENGINEERING AND TECHNOLOGY, LAHORE
INTERNSHIP REPORT
WAPDA-Hydal Operations
Submitted To:
General Manager (Hydal Operations)
Mr.Taseer Iqbal
Submitted By:
Saboora Khatoon 2009-ME-140
Wardah Khalid 2009-ME-145
Faiza Rehman 2009-ME-147
Samavia Taseer 2009-ME-150
From 2nd
July to 1st
August

2
INTRODUCTION TO ENERGY
The capacity to do a work is energy……………..
We are greatly dependent upon energy. God gave us several forms of natural energy to help us
live productively on earth. He gave man the intelligence to learn how to use different forms of
energy in creative ways.
Energy Sources
The different things from which we get the energy are called as Energy Sources. There are two
types of energy sources.
1. Conventional or Non-Renewable Energy Sources
2. Non-Conventional or Renewable Energy Sources
1. Conventional or Non-Renewable Energy Sources:
The energy sources, which we are using from long time and which are in danger of
exhausting, are called as Conventional OR Non-Renewable Energy Sources e. g. coal,
petroleum products, nuclear fuels etc.
2. Non-Conventional or Renewable Energy Sources:
These are the sources, which can be recovered and reused. i. e. they can be used again
and again to generate energy because of the renewal of their energy. e.g. hydel, wind,
geothermal etc.

3
Power and Energy
 We can differentiate between power and energy as the utilization of power is
energy.
 We achieve power from generators in the form of mega watts, but this power
when utilized for a time interval in any equipment, it is energy. Now, this energy
gives the ability to do work.
 The consumption of power for time is expressed in the form of energy. Our
purpose is to generate power.
Types of Power Generation
We use conventional and non-conventional sources of energy for power generation. Thermal
power generation is an expensive method. It needs a lot of auxiliaries and the system is overall
complicated. Wind potential can be used for power generation but it requires greater
restrictions. The selection of site and its climatic conditions are very important for wind,
nuclear, geothermal power generation. Moreover, the drastic weather conditions cause the
damage of heavy equipment which in run becomes a loss of lives and also capital. Keeping all
the aspects in view, hydro-electric power plants are much more reliable and efficient than the
fossil fuel fired plants.
 Hydroelectric Power
Hydro power is currently the world's largest renewable source of electricity, accounting for 6%
of worldwide energy supply or about 15% of the world's electricity.
Electricity produced from generators driven by water turbines that convert the energy in falling
or fast-flowing water to mechanical energy. Water at a higher elevation flows downward
through large pipes or tunnels (penstocks). The falling water rotates turbines, which drive the
generators, which convert the turbines' mechanical energy into electricity.
Advantages
 Simple in construction
 No Fuel consumption
 No pollution
 Low Running Cost
 Less Maintenance
 High efficiency with proper attendance
of plant
 Reutilization of water for Irrigation
Disadvantages
 High Capital or Initial cost i.e. of civil
works, equipment etc
 Power generation effects during dry
season
 High cost of transmission lines

4
HYDEL POTENTIAL IN PAKISTAN
Taking a general over view of different locations in Pakistan, Pakistan WAPDA has traced out
about 50,000 MW hydro-electric potential. But due to limited financial resources and political
issues of the country, unfortunately only 6516 MW is the total installed capacity of HPP. There
are 14 different Hydel power stations working under WAPDA in Pakistan.
In 1960, with the co-operation of World Bank, a treaty was signed between India and Pakistan
for water distribution.
Salient Features of the Indus Basin Water Treaty
Provisions regarding the Eastern Rivers:
1. All the waters of the Eastern Rivers shall be available for the unrestricted use of India.
2. Except for domestic and non-consumptive uses, Pakistan shall be under an obligation to
let flow, and shall not permit any interference with, the waters of Sutlej Main and the
Ravi Main in the reaches where these rivers flow in Pakistan and have not yet finally
crossed into Pakistan.
3. All the waters, while flowing in Pakistan, of any tributary which, in its natural course
joins the Sutlej Main or the Ravi Main after these rivers have finally crossed into
Pakistan shall be available for the unrestricted use of Pakistan.
Provisions regarding the Western Rivers:
1. Pakistan shall receive for unrestricted use all those waters of the western rivers.
2. India shall be under an obligation to let flow all the waters of the Western rivers, and
shall not permit any interference with these waters.
Provisions regarding the Eastern and Western Rivers:
1. Pakistan shall use its best endeavors to construct and bring into operation a system of
works that will accomplish the replacement from the Western rivers (and other sources
of ) the water supplies for irrigation canals in Pakistan, which on 15th August, 1947
were dependent on water supplies from the Eastern rivers.
2. The use of the natural channels of the rivers for the discharge of flood or other access
waters shall be free and not subject to limitation by either party, or neither party shall
have any claim against the other in respect of any damage caused by such use.
3. Each party declares its intention to prevent, as far as practicable, undue pollution of the
waters and agrees to ensure that, before any sewage or industrial waste is allowed to
flow into the rivers.

5
TARBELA HYDEL POWER STATION
Tarbela Dam is one of the world’s largest earth and rock filled Dam and greatest water
resources development project which was completed in 1976 as a component part of Indus
Basin Project. The Dam is built on one of the World’s largest rivers – the Indus known as the
“Abbasin” or the father of rivers.
Project
Project cost of Tarbela hydel power station was 16.417 billion Rupees and was funded by
ADB/KFW.
Specifications
Main Spillway Capacity = 6, 50,000 cusecs
Type = Earth and Rock fill
Height = 485 ft (above river bed)
Length = 9000 ft
Total Capacity = 3478 MW
Max. op. level = 1550
Min. op. level = 1378
Turbine (Francis-Vertical)
UNITS 1-4 5-6 7-8 9-10 11-14
Rated Head ft. 378 378 378 378 385
Manufacturer Hitachi
Japan
DEW Canada DEW Canada DBS
Canada
DBS
Canada
Capacity /unit(MW) 175 175 175 175 432
Total installed
capacity(MW)
700 350 350 350 1728
Commissioning JULY-1977 DEC-1982 DEC-1982 APR-1985 FEB-1993
Generator (Umbrella)
UNITS 1-4 5-6 7-8 9-10 11-14
Output(MVA) 205.882 184.210 184.210 184.210 480
Output( P.F ) 0.85 0.95 0.95 0.95 0.90
Output(MW) 175 175 175 175 432
Rated
Voltage(KV)
13.8 13.8 13.8 13.8 18.2
Manufacturer Hitachi
Japan
CGE
Canada
CGE
Canada
Hitachi
Japan
Siemens-ABB
Germany
Transformer
UNITS 1-4 5-6 7-8 9-10 11-14
Capability(MVA/Phase) 79 71 71 71 160
Voltage Ratio 13.2/220 13.2/500 13.2/500 13.2/500 25.0/500
Manufacturer Jeumount-
Scheider
ASEA Canada
Hitachi Japan
Hitachi
japan
Jeumount-
Scheider
Ansaldo
Italy

6
MANGLA HYDEL POWER STATION
Location
Mangla Dam Project was actually conceived in 1950's as a multipurpose project to be
constructed at a place called Mangla on river Jhelum located about 30 km upstream of
Jhelum city (120 km from Capital Islamabad).
Project
The initial investigation and its feasibility studies were completed in 1958. Later on the project
was included in the Indus Basin Project. The construction of Mangla Dam was started in 1962
and completed in 1967.it was funded by USA,UK ,Australia, Germany, Newzeland, Pak &India
IBRD world Bank ,CZECH-Pak barter, Credit Loan Marubini, Wapda&CZECH loan. Project cost
was 3.455 billion rupees.
Specifications
Discharge = 8,70, 000 cusecs
Total no. of units = 10 x 100 MW
Total installed Capacity = 1000 MW
Water Head = 296 ft
Max./Min. op. level (ft) = 12426/1040
Turbine (Francis)
UNITS 1~4 5~6 7~8 9~10
Output (BHP) 138000 138000 138000 138000
Rated Head (Ft. of Water) 295 295 295 295
Make
Mitsubishi
Japan
CKD Blansko
(Czech.)
Escherwyse-
ACEC Belgium
SKODA
(Czech.)
Capacity/unit(MW) 100 100 100 100
Total installed capacity(MW) 400 200 200 200
Commissioning 1967-1969 MAR-1974 1981 1993-1994
Generator (umbrella)
UNITS 1~4 5~6 7~8 9~10
Output (MVA) 125 125 125 125
Output (MW) 100 100 100 100
Output (P.F) 0.8 0.8 0.8 0.8
Output (K.V) 13.2 13.2 13.2 13.2
Rated Speed (RPM) 166.7 166.7 166.7 166.7
Make Hitachi Japan Skoda Czech. Hitachi Japan Skoda Czech.
Transformer
UNITS 1~4 5~6 7~8 9~10
Capability (MVA) 138 138 138 144
Voltage Ratio (KV)
• 12.5 / 132 [Unit 1~2]
• 12.5 / 220 [Unit 3~4]
12.5/220 12.5/220 12.5/220
Make
Savigliano Italy [1&4]
Skoda Czech. [2&3]
Savigliano
Italy
Italtrafo [Unit-7]
Skoda [Unit-8]
Skoda
Czech.

7
WARSAK HYDEL POWER STATION
Location
Warsak Hydro Electric Power Project is located on River Kabul at about 30 km from Peshawar in
North-West Frontier Province of Pakistan.
Project
The project financed by Canadian Government was completed under COLOMBO PLAN in two
phases. It was completed in 1960 at a total cost of Rs. 394.98 million in Phase 1. Two additional
generating units each of 41.48 MW were added in 1980-81 at a cost of Rs. 106.25 million as
second phase of the project.It was funded by PLAN & CIDA.
Specifications
Total installed Capacity = 242.96 MW
Area = 4 Sq. miles
Max. op. level (ft) = 1270
Min. op. level (ft) = 1270
Turbine (Francis-Vertical)
UNITS 1-4 5-6
Output (BHP) 55,000 57,000
Net Head 144 ft 144 ft
Speed 136.4 RPM 136.4 RPM
Manufacturer Dominion Engg. Co. Canada Dominion Engg. Co. Canada
commissioning JULY-1960 MARCH-1981
UNITS 1-4 5-6
Output(MW) 40 41.5
Output(P.F) 1.0 0.85
Rated Speed 136.3 RPM 136.3 RPM
Manufacturer Canadian General Elec. Co. Ltd Canadian General Elec. Co. Ltd
Transformer
UNITS 1-4 5-6
Capacity 13.33/Phase 48.8 three Phase
Voltage Ratio 11/132 KV 11/132 KV
Manufacturer Saranti, Canada Westing house
Switch yard
No. of 132 KV feeder/breaker = 4 / 06
Scheme Layout = Double Bus bar/ One and half breaker system
Tunnels/penstock = 6

8
GHAZI BAROTHA HYDEL POWER STATION
Location
Ghazi Barotha Hydropower Project is located on the Indus River downstream of Tarbela Dam. it
reaches Indus River drops by 76 m in a distance of 63 km.
Project
This Project possesses the minimum of environmental and social impacts. Ghazi Barotha
Hydropower Project consists of three main components. The Barrage, the Power Channel and
the Power Complex.It was funded by World bank/ADB JAPAN Bank Int.Coop./KFW/Eurpean
Invst Bank /Islamic Bank.Project cost was 94.733 billion rupees.
Specifications
Discharge Capacity = 1,600 cusics
Total installed Capacity = 5 x 290 MW
Turbine (Francis)
Number of Units 1-4 5
Output (MW) 290 290
Rated Head (Feet) 226 226
Manufacturer
M/S VOITH HYDRO
GERMANY
M/S VOITH HYDRO GERMANY
Capacity/unit(MW) 290 290
Commissioning 7-2003 3-2004
Output (MVA) 322.2
Output (P.F) 0.9 LAGGING
Rated speed (rpm) 100
Manufacturer M/S TOSHIBA CORPORATION JAPAN
Transformer
Capacity (MVA) 3X107.5
Voltage ratio (KV) LV=18 KV, H V=5153 KV
Manufacturer SIEMENS ABB
Switch yard
Scheme Layout = Double Bus bar/ One and half breaker system

9
CHASHMA HYDEL POWER STATION
Location
It is located on the River Indus close to the right embank of Chashma Barrage.It is low head
hydel power station utilizing available head of 4-13 meters.
Project
Its operation is dictated by the release downstream Chashma Reservoir being controlled by the
Indus River System Authority (IRSA). The project cost is 21082 million rupees.It was funded by
ADB,CITY Bank,Japan,Pakistan,French,Protocol,Suplementory credit Agricole indonsuez France.
Specifications
Total Capacity = 8 x 23 MW
Generation voltage = 11 KV
Turbine (Bulb)
Type Fuji Japan
Rotation Speed 21 ft
Runner Diameter 21 ft
Guide Vanes 16
Discharge unit 8829 cusecs
Head available 13 m to 38 m
Rated head 27.4 ft
commissioning 2000-2001
Transformer
Type GE Alsthon France
Voltage 132 KV
Rated Capacity 26 MVA
Generator (Bulb)
Type Fuji Japan
Rated Capacity 23 MVA
Power factor 0.9
Voltage 11 KV
Switch yard
Scheme Layout = Double Bus bar/ Double breaker system

10
RASUL HYDEL POWER STATION
Location
It is first Hydel Power Station after creation of Pakistan. Hydel Power Station is situated on
upper Jhelum Canal (UJC) 80 km downstream from its source i-e New Borg Escape ,Mangla. The
power house is operated as base-load and it is connected to National Grid System through 132
KV and 66 KV transmission lines.
Project.
The cost of project is 20.33 Millions.It was funded by N.A.
Specifications
Total Capacity = 11 X 2 MW
Generation Voltage = 11 KV
Transformation Voltage = 132 KV
Reservoir = River of Canal
Installation = in 1952
Turbine (Kaplan)
Type Kaplan Boving UK
Discharge / unit 1812 cusecs
Rated Head(ft) 85
Commissioning July-1952
Type Umbrella/British Thomson UK
Output(MVA) 12.5
Output(P.F) 0.88
Output(KV) 11
Rated Speed 214 RPM
Transformer
Capacity 2*12.5
Voltage ratio 11/66 KV
Transmission line 132 KV/2; 66 KV/2
Switch yard
Scheme Layout = Single Bus bar/ single breaker system

11
SHADIWAL HYDEL POWER STATION
Location
Shadiwal Hydel Power Station District Gujarat is situated at the tail of upper Jhelum Canal near
Shadiwal town at a distance of 14 km from Gujarat which takes off from Jhelum River at Mangla
and falls into Chanab River upstream of Khanki Head works after Shadiwal Power station.
Project
This project was completed through Colombo plan financed jointly by the government of
Canada and Pakistan.Project cost was 0.044 billion rupees.
Specifications
Total capacity = 2 x 6.75 MW
Transformation voltage = 132 KV
Water head = 23 ft
Manufacturer of turbine = Dominion Canada
Manufacturer of generator = Umbrella /Canadian GEC
Spillway gates = 6
Siphon spillway = 2
Turbine (Kaplan)
Type Kaplan Dominion Canada
Discharge /unit 3900 cusecs
Commissioning JAN-1961
Output(MVA) 7.5 MVA
Output(P.F) 0.9 Lagging
Output(KV) 11 KV
Rated Speed 83.3 RPM
Transformer
Capacity 4 x 5 Single
Voltage Ratio 3.3/11 KV
Manufacturer Pioneer Electric Ltd. Canada
Transmission Line 132 KV/1
Switch yard
Scheme Layout = Single Bus bar/ Single breaker system

12
NANDIPUR HYDEL POWER STATION
Location
It is situated on upper Chenab canal (UCC) near Nandipur village at a distance of about 10 km
from Gujranwala-Sialkot road.
Project
Project cost was 0.062 billion rupees. It was funded by N.A.
Specifications
Total capacity = 3 x 4.6 MW
Generation Voltage = 3.3 KV
Transformation Voltage = 66 KV
Water Head = 22 ft
Manufacturer of turbine = Kaplan Litostroj Yugoslavia
Manufacturer of generator = umbrella /Rade Koncer Yugoslavia
Turbine (kaplan)
Output 6500 BHP
Discharge 3040 cusecs
Head Water 22 ft
Runaway Speed 280 RPM
Rayed speed 107 RPM
Power transformer
Output 2*8500 KVA
Voltage 11/66 KV
Current 446/74.5 Amps
Connection YD-5
Impedance 8.6%
Switch yard
Scheme Layout = Double Bus bar/ Single breaker system
Output 3*5750 KVA
Power Factor 0.8
Rated Current 1010 Amps
Voltage 3.3 KV
No. of Poles 56
commissioning MAR-1963

13
CHICHCHOKI HYDEL POWER STATION
Location
Chichoki Hydel Power Station is located on Upper Chanab Canal near village Joyanwala about
20 Km from sheikhupura city.
Project
Power Station was commissioned on Aug 1959 the project cost is 30.55 million.It was funded
by N.A.
Specifications
Total Capacity = 3 x 4.4 MW
Generation voltage = 3.3 KV
Water head = 25 ft
Manufacturer of turbine = Kaplan/Litostroj Yugosalavia
Manufacturer of generator = Umbrella / Rade Koncer Yugosalavia
Reservoir = Run of Canal
Turbine (Kaplan)
Type Kaplan
Rated head 25 ft
Discharge/unit 2700 cusecs
Commissioning Aug-1959
Type Umbrella
Output(MVA) 5.6 MVA
Output(P.F) 0.8
Output(KV) 3.3 KV
Rated Speed 107 RPM
Transformer
Capacity 2*15
Voltage Ratio 11/66 KV
Transmission Line 11 KV/2
Switch yard

14
DARGAI HYDEL POWER STATION
Location
Dargai Hydel Power Station is located on Upper Swat Canal in Malakand agency near Dargai.
Project
The project was funded by N.A. The project cost is 30.86 Million.
Specifications
Total capacity = 4 x 5 MW
Reservoir = Run of Canal
Manufacturer of turbine = SM smith USA
Manufacturer of generator = Westings House
Gross head station = 18.9 m
Discharge/ unit = 15.8 m³/s
Turbine (Francis)
Type Kaplan
Rated Head 243 ft
commissioning Dec-1952
Output(MVA) 5.88 MVA
Output(P.F) 0.85
Output(KV) 11 KV
Rated Speed 500 RPM
Transformer
Capacity 2*15 ; 1*12.5
Voltage Ratio 11/132 KV ; 11/60 KV
Transmission line 132 KV/2 ; 66 KV/1
Switch yard
No. of 132 KV feeder/breaker= 1 / 3

15
RENALA HYDEL POWER STATION
Location
The existing Renala Hydel Power Station is located on RD (160 to 686) near Renala town on
Lower Bari Doab Canal off taking from Head Baloki.
Project
This was built in 1925 by Sir Ganga Ram for low head pumps for irrigation to fields.It was
funded by Ganga Ram.
Specifications
Total Capacity = 5 x 0.22 MW
Transformation voltage = 11 kV
Turbine (Francis)
Type Horizontal Francis
Manufacturer Vicker England
Speed 100 RPM
BHP 385 hp
Total Rated Discharge 74 cusecs
Wicket Gates 16
Stay Vanes 16
Runner 4
Runner Blade 16
Commissioning Mar-1925
Transformer
No. of Transformer 2
Nominal Rating 2 MVA
High Voltage 11 KV
Low Voltage 0.4 KV
Generator (CEC.UK)
Rated output 275 KVA
Generation Voltage 33000 V
No. of Poles 10
Rated Capacity 220 KV
Switch yard

16
KURRAM GARHI HYDEL POWER STATION
Location
Khurram Ghari Hydel Power Station is located on river Khurram about 10 Km North West of
Bannu city.
Project
The cost of the project is 4.07 Million. The project was funded by N.A.
Specifications
Total capacity = 4 x 1 MW
Water Head = 60 ft
Manufacturer of turbine = Siemens
Manufacturer of generator = Siemens
Reservoir = Run of river
Turbine (Siemens)
Type Francis
Rated Head 18.3 ft
commissioning Feb-1958
Generator (Siemens)
Output(P.F) 0.85
Output(KV) 3.3 KV
Rated Speed 428 RPM
Transformer
Switch yard
No. of 66 KV breaker = 1
Scheme Layout = Single Bus bar/ Single breaker system

17
CHITRAL HYDEL POWER STATION
Location
Chitral Hydel Power Station is located on Ludko River Gram Chashma road, 7 KM East of Chitral
town.
Project
Project cost was 19.47 million. It was funded by N.A.
Specifications
No. of units = 4
Capacity of each unit = 1-2 units (0.3 MW) & 3-4 units (0.2 MW)
Total Capacity = 1 MW
Water head = 110 ft
Manufacturer of turbine = Ossberger W.G
Manufacturer of generator = AEG W.G
Turbine (Ossberger Germany)
Type Kaplan
Rated Head Unit 1-2(98 ft) & Unit 3-4(105 ft)
Discharge/unit Unit 1-2(1050 Cfs) & Unit 3-4(1256 Cfs)
Commissioning 1975 -1982
Generator (GMBH Germany)
Output(P.F) 0.8
Output(KV) 0.42 KV
Rated Speed Unit 1-2(1500 RPM) & Unit 3-4(1000 RPM)
Transformer
Manufacturer GEC
Switch yard

18
KHAN KHWAR HYDROPOWER PROJECT
Location
The Project is located on Khan Khwar River, a tributary of Indus River near Besham District
Shangla in N.W.F.P. at a distance of 245 Km from Islamabad.
Specifications
Design Discharge = 35 m³/s
Gross Head = 252 m
Headrace Tunnel =4.557 km
Installed Capacity =72 MW
Energy per annum =306 GWh
NO. and types of unit =3(2*34+1*4)MW Francis
Speed of Turbine =500 rpm
Generator
Speed 500 rpm
Output 34 MW/40 MVA
Turbine
Discharge/unit 16.8 m³/s
Discharge for Auxiliary
unit
2 m³/s
No. of unit 3
Type of unit Francis, Turgo
Capacity of unit#1 34
Commissioning Feb 2011
Energy Output
Installed capacity (2 Francis) 68 MW
Auxiliary Capacity 4MW
Switch yard
No. of 11 KV feeder = 1
No. of 132 KV breaker = 5
Scheme layout = Single Bus bar/ Single breaker system

19
HYDROELECTRIC POWER PLANT SCHEME LAYOUT
Hydroelectric power plants convert the hydraulic potential energy from water into electrical
energy. Such plants are suitable were water with suitable head are available. The different parts
of a hydroelectric power plant are
 Catchment Area
The areas from where water comes in the reservoir is called catchment area .e.g.
mountains, rivers, lakes etc.
 Reservoir
The area where water is stored is called reservoir.
 Dam
Dams are structures built over rivers to stop the water flow and form a reservoir. The
reservoir stores the water flowing down the river. This water is diverted to turbines in
power stations. The dams collect water during the rainy season and stores it, thus
allowing for a steady flow through the turbines throughout the year. Dams are also used
for controlling floods and irrigation. The dams should be water-tight and should be able
to withstand the pressure exerted by the water on it. There are different types of dams
such as arch dams, gravity dams and buttress dams.
The height of water in the dam is called head race.
 Spillway
A spillway is a way for spilling of water from dams. It is used to provide for the release of
flood water from a dam. It is used to prevent over toping of the dams which could result
in damage or failure of dams.
There are two types of spillways: Controlled type & Uncontrolled type
The uncontrolled types start releasing water upon water rising above a particular level. In case
of the controlled type, regulation of flow is possible.
 Penstock and Tunnel
Penstocks are pipes which carry water from the reservoir to the turbines inside power
station. They are usually made of steel and are equipped with gate systems. Water
under high pressure flows through the penstock. A tunnel serves the same purpose as a
penstock. It is used when an obstruction is present between the dam and power station
such as a mountain.
 Surge Tank
Surge tanks are tanks connected to the water conductor system. It serves the purpose

20
of reducing water hammering in pipes which can cause damage to pipes. The sudden
surge of water in penstock is taken by the surge tank, and when the water requirements
increase, it supplies the collected water thereby regulating water flow and pressure
inside the penstock.
 Power Station
Power station contains a turbine coupled to a generator. The water brought to the
power station rotates the vanes of the turbine producing torque and rotation of turbine
shaft. This rotational torque is transferred to the generator and is converted into
electricity. The used water is released through the tail race. The difference between
head race and tail race is called gross head and by subtracting the frictional losses we
get the net head available to the turbine for generation of electricity.

21
SOURCES OF WATER AND SELECTION OF TURBINES
Types of Reservoirs
a- Run off River Plants
b- Daily Storage Plant
c- Seasonal Storage Plants
d- Pump Storage Plants
a. Run-of-river facilities use only the natural flow of the river to operate the turbine. E.g.
Nandipur station.
b. Daily storage plants store water from the river in a small pond that is passed through
the turbine blades. This water storage is sufficient for a day use. i.e., at Ghazi Brotha
station.
c. Seasonal Storage plants use a dam to capture water in a reservoir. This stored water
is released from the reservoir through turbines at the rate required to meet changing
electricity needs or other needs such as flood control, fish passage, irrigation,
navigation, and recreation. Mangla and Tarbela are large dams in Pakistan.
d. Pump storage plants have specially designed turbines. These turbines have the ability
to generate electricity the conventional way when water is delivered through penstocks
to the turbines from a reservoir. They can also be reversed and used as pumps to lift
water from the powerhouse back up into the reservoir where the water is stored for
later use. Such type of plant is being constructed in Canada not available in Pakistan.
Turbine
A hydraulic turbine consists of a runner connected to a shaft for producing prime motive
power, a mechanism for controlling water flow to the runner and water passages leading to the
control mechanism and away from the runner.
Fundamental Formula
HpT = ( HxQxW)/550 = HQ/8.82
HpT= theoretical horse power
W = weight of one cubic foot of water ( approximate,62.4 lb)
Q = discharge of water H= Water head in feet

22
Synchronous Speed
Hydraulic turbines are direct-connected to a-c generator, hence must operate at some speed
nearest the best speed from a hydraulic and mechanical stand point
The synchronous speed of a generator is a speed at which it is designed
𝑁 =
120𝑓
𝑃
Types of Hydraulic Turbines
A. According to the type of flow of water
The type of flow of water consider three axis
1. Axis along the shaft (Propeller and Kaplan turbines for 70 to 110 feet
head)
2. Axis along the radius ( Francis Turbine for head of 800 feet)
3. Axis along the tangential flow. ( Pelton wheel for 1300 feet head and above )
B. According to Water Head
1- Up to 70 feet Propeller Type ( either fixed or adjustable )
2- 70 ft to 110 ft Propeller Type or Francis Type
3- 110 ft to 800 ft Francis Type
4- 800 ft to 1300 ft Francis or Impulse type
5- More than 1300 ft Impulse ( Pelton wheel )
C. According to the action on fluid
1- Impulse Turbine
2- Reaction Turbine

23
1. Impulse Turbine
A free jet of water discharging into an aerated space impinges on the buckets of the runner and
is controlled by a needle- type nozzle .The power output is controlled either by actuating the
needle in the centre of the nozzle or by deflecting the stream between nozzle and runner by
means of a jet deflector.
Types of Impulse Turbine
a) Turgo turbine
b) Cross flow turbine
2. Reaction Turbine
These turbines work due to reaction of coming water on the water in which runner is
submerged. Water enters in the spiral casing from the intake and passing through the
stay/guide vanes it enters into the runner.
The water enters under pressure and flows over the vanes. As the water flowing over the
vanes, is under pressure, therefore the wheel of the turbine (runner) runs full and may be
submerged below the tailrace level. The pressure head of water while flowing over the vanes is
converted into velocity head and is finally reduced to the atmospheric pressure, before leaving
the runner.Power is controlled by actuating the movable wicket gates either manually or by a
motor or by a governor.
Types of Reaction Turbine
A- Depending upon the direction of the water flow
1. Radial flow turbines (Francis ) (Inward flow turbines and out ward flow turbines)
2. Axial flow turbines (Kaplan) (Movable and Fixed blade types)
3. Mixed flow turbines (Francis)
B- Depending upon the water head
1. Francis (For medium head)
2. Kaplan (For low head)

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COMPARISON OF IMPULSE AND REACTION TURBINES
S.No. IMPULSE TURBINES REACTION TURBINES
1 The entire available energy of water is
first converted into kinetic energy.
The available energy of water is not
converted from one form into other.
2 The water flows through the nozzles
and impinges on the buckets which
are used to the outer periphery of the
wheel (runner).
The water is guided by the guide vanes to
flow over the moving blades.
3 The water impinges on the buckets
with kinetic energy.
The water glides over the moving blades
with pressure energy.
4 The pressure of the flowing water
remains unchanged and is equal to
the atmospheric pressure.
The pressure of flowing water is reduced
after gliding over the blades.
5 It is not essential that the runner
should run full .Moreover there
should be free access of air between
the vanes and the wheel ( runner.)
It is essential that the runner should
always run full and kept ful of power.
6 The water may be admitted over a
part of the circumference or over the
whole circumference of the wheel (
runner.)
The water must be entered over the
whole circumference of the runner.
7 It is possible to regulate the flow
without loss.
It is not possible to regulate the flow
without loss.

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FRANCIS TURBINE
The basic components of Francis turbine are:
1) Runner
Runner is usually made of Carbon steel for small outputs and of silicon steel or chrome steel for
larger outputs. Basically it consists of two rings connected by blades (vanes). Profile of the
blade is important thing and better design gives maximum output. This design changes from
turbine to turbine.
The water enters the turbine (runner) radially and leaves the runner axially in Francis turbines.
It needs its annual maintenance because it remains under the pressure of water constantly.
2) Spiral Casing
It is a tunnel moving all around the runner. As it move round the runner its diameter decreases
gradually. The diameter is decreased to keep the pressure same so that there will be no jerk or
sudden vibration .This casing is very large so it is divided into segments of suitable size for
transportation.
A great care is maintained in dispatching and receiving the segments and should be in sequence
so there is no problem for transportation, handling and erecting. After erecting, alignment of
the received pieces is made and then welded.
After welding, X-ray tests are made of the welding. This welding is done by qualified welders.
The spiral casing is made with hook type arrangement on around it. Then all the casing is
imbedded in the concrete completely. The high pressure of the water will be balanced with
concrete block around the casing.
3) Draft Tube Assembly
It is very similar to spiral casing but it only takes the water, which is drained by runner. There
are many shapes of draft tubes. In Mangla, the elbow shape tube is used. Its material is normal
steel or alloy steel. Firstly it is designed, manufactured, dismantle, shifted to site, brought to
site, erected on site, alignment is made and then welded. It is also brought in pieces or
segments. Its assembly begins from the draft tube outlet. And followed to concrete block on all
sides. All sides of the tube are provided hook type arrangement. The out lets are inverted
funnel type. They are always dipped in water so that the water coming from runner will lose its
remaining energy to overcome the thrust of water already there.
4) Draft Tube Cone
It is erected in the last and after the concrete foundation; an opening (corridor) is made to go
into the draft tube cone for the inspection of the runner. There are no. of small holes in the
upper part of cone which have bushings in which the bottom neck of guide vane is housed.

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5) Bottom Ring
It is a ring placed at the top of draft tube cone. It has no. of holes. The bushes are housed in the
holes in which the bottom neck of the guide vanes is placed.
6) Stay Ring / Stay Vanes
When water enters to spiral casing, it has great pressure, it is not allowed to go into the blades
of runner directly, and otherwise it will break all the things. So one ring is welded to the inner
portion of spiral casing all around the diameter of casing. On this ring some curved spaces are
made in to form of blade, these are called fixed vanes. Intensity of pressure of water is broken
by the vanes, and is guided towards to guide vane. The reinforcement of the spiral casing is
done by ring.
7) Inner & Outer Top Cover
These are steel rings which are used to cover top side of the runner in turbine pit.
8) Stuffing Box
When water enters to runner, it tries to go up along the shaft to maintain its level, so there
should be something, which can stop this water; stuffing box is that arrangement which do this
work. It is around the shaft. Firstly, there is a sleeve which is shrinking fitted to main shaft. After
this, the carbon seals are fixed in form of segments around the sleeve. Around this carbon seals
a steel ring is installed.. These seals are further reinforced by a steel spring which is kept in
tension around the seals. All this arrangement is covered with semi-circular cover and is called
stuffing box. Carbon is soft material as compared to sleeve material, so after wear & tear it can
be replaced. Due to moving of shaft, heat is produced so cooling is very essential. The stuffing
box is completely filled with water which has pressure more than the pressure of water
coming from the runner
9) Main Guide Bearing
In order to maintain the vertical alignment a bearing is fitted called main guide bearing . It has
no. of pads which are fitted around the shaft, supported by shaft collar provided in the shaft.
These pads are put together by a cover. These pads are completely filled with oil. Heat
produced, is absorbed by the oil. This hot oil is cooled by the water which is provide in the form
of jackets. There are copper tubes in the jacket in which water is coming, takes the heat from
oil and goes back.
10) Wicket Gates, Servo Motors & Regulating Ring
Wicket Gate is a solid piece which has two edges, one is face and other is tail. On tail its
thickness is less, when it close, the face of other vane overlap the tail of other vane. So there is

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no clearance for water. The weight of one guide vane is 2 tons. It is operated by the ring
through flexible link mechanism.
Servo motors are used to move a ring which is indirectly connected to guide vanes. These
motors are oil operated. They produce a force which moves the regulating ring of which the
lower portion is connected to the stopper head of guide vane by link mechanism. The pressure
of oil required to operate the servomotor is 340Psi. When the ring moves anti-clock wise, the
guide vanes will open and in clock wise it will close the guide vanes. The motors operate in this
way that the force produced will be doubled, they do not cancel the force each other.
11) Irrigation Valve
This valve serves two purposes.
i. Irrigation purpose, when the irrigation demand is not fulfilled from Power house,
then this valve is opened
ii. For safety, It is used for the safety of tunnel from the water hammering when
machine is tripped.
This valve is operated by servomotors, which are connected two separate shafts, which move
the sleeve. This sleeve covers the grooves and when this sleeve moves, these grooves are
uncovered and valve opens. This valve opens within few seconds. The opening of the valve and
opening of guide vanes are interconnected. When guide vanes are taking more water, then this
valve discharges less water. This valve is direct extension of spiral casing.
Cavitations Phenomenon, Its Effects And Remedies
The water is conveyed to the turbine in pipes or conduits called penstocks. If the water
pressure at any point reaches the vapor pressure, the vapor pockets or cavities are said to be
formed. Hence the formation of vapor is called cavitations.
When the pressure further increases the vapor pressure, a violent collapse takes place which is
known as the water hammering. The pressure created may be so high that it causes pitting i.e.
tearing off the surface of material.
Remedies
The cavitations can be avoided by the following methods.
1. By providing smooth curvatures for the flow of water.
2. By using tough and high resistive material.
3. By using steel line where there is a possibility of cavitations

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AUXILIARY SYSTEMS OF UNIT
1. Cooling Water System
2. Lubrication System
3. Governor Oil System / Inlet Valve Oil system
4. Thrust Bearing oil Injection System
5. Brake System
6. Runner Air Aspiration System
 Governor air system
 Break air system
 Stainer air system
 General air compressor system
 Power swing compressor system
7. High pressure oil injection system
8. Jacking oil system
9. Firefighting system
10. Drainage system
11. Dewatering system
Cooling Water System
The cooling is essential for every system in which heat is produced .Every material has its own
specified designed temperature .When temperature of that part increases from that
temperature, that wear & tear of that part occurs. The increase in normal rate of wear & tear
decreases the life of that part. The cooling increases the life of that part.
Lubrication System
Lubrication is provided between any two moving or sliding parts to ensure easy movement and
to reduce the friction. Friction creates heat and wear & tear of the relative parts. Grease
Alvania EP-0 and Albania -2 are used in central grease system.

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GOVERNORS
Function
Governors serve three basic purposes:
a) Maintain a speed selected by the operator which is within the range of the governor.
b) Prevent over-speed which may cause engine damage.
c) Limit both high and low speeds.
Types
The four basic types of governors are as follows:
1. Mechanical Governor
Mechanical governors, sometimes, referred to as centrifugal governors. Centrifugal flyweight
style that relies on a set of rotating flyweights and a control spring; used since the inception of
the diesel engine to control its speed. Power-assisted servo mechanical style that operates
similar to the mechanical centrifugal flyweight but use engine oil under pressure to move the
operating linkage. Hydraulic governor that relies on the movement of a pilot valve plunger to
control pressurized oil flow to a power piston, which, in turn, moves the fuel control
mechanism.
2. Pneumatic Governor
Pneumatic governor that is responsive to the airflow (vacuum) in the intake manifold of an
engine. A diaphragm within the governor housing is connected to the fuel control linkage
that changes its setting with increases or decreases in the vacuum.
3. Electromechanical Governor
Electromechanical governor uses a magnetic speed pickup sensor on an engine-driven
component to monitor the rpm of the engine. The sensor sends a voltage signal to an electronic
control unit that controls the current flow to a mechanical actuator connected to the fuel
linkage.
4. Electronic Governor
Electronic governor uses magnetic speed sensor to monitor the rpm of the engine. The sensor
continuously feeds information back to the ECM (electronic control module). The ECM then
computes all the information sent from all other engine sensors, such as the throttle

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position sensor, turbocharger-boost sensor, engine oil pressure and temperature sensor,
engine coolant sensor, and fuel temperature to limit engine speed.
The governors, used on heavy-duty truck applications and construction equipment, fall into
one of two basic categories:
A. Limiting-speed governors sometimes referred to as minimum/maximum models
since they are intended to control the idle and maximum speed settings of the engine.
Normally there is no governor control in the intermediate range, being regulated by the
position of the throttle linkage.
B. Variable-speed or all range governors that are designed to control the speed of the
engine regardless of the throttle setting.
Other types of governors used on diesel engines are as follows:
a. Constant-speed, intended to maintain the engine at a single speed from no load to
full load.
b. Load limiting, to limit the load applied to the engine at any given speed. It
prevents overloading the engine at whatever speed it may be running.
c. Load-control, used for adjusting to the amount of load applied at the engine to suit
the speed at which it is set to run.
d. Pressure regulating, used on an engine driving a pump to maintain a constant
inlet or outlet pressure on the pump. At this time on heavy-duty truck and
construction equipment applications, straight mechanically designed
units dominate the governor used on non electronic fuel injection systems.
Stability
Stability is the ability to maintain a desired engine speed without fluctuating. Instability results
in hunting or oscillating due to over correction. Excessive stability results in a dead-beat
governor or one that does not correct sufficiently for load changes.
Sensitivity
Sensitivity is the percent of speed change required to produce a corrective movement of the
fuel control mechanism. High governor sensitivity will help keep the engine operating at a
constant speed.

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PUMPS
A pump is defined as ' A machine used to add energy to a liquid’.
The flow of liquid is affected by friction, pipe size, liquid viscosity and the bends and fittings in
the piping. To overcome flow problems, and to move liquids from place to place, against a
higher pressure or to a higher elevation, energy must be added to the liquid. To add the
required energy to liquids, we use ' PUMPS '.
Pumps come in many types and sizes. The type depends on the function the pump is to perform
and the size (and speed) depends on the amount (volume) of liquid to be moved in a given
time.
TYPES OF PUMP
Most pumps fall into two main categories.
 CENTRIFUGAL PUMPS
 POSITIVE DISPLACEMENT PUMPS
CENTRIFUGAL PUMPS
Modern process plants use powerful centrifugal pumps, primarily because of the following
factors:
1. The low initial cost.
2. Low maintenance costs.
3. Simple in operation.
4. Ability to operate under a wide variety of
conditions.
5. Give a smooth, continuous flow, free from
pulsation.
Parts
A centrifugal pump is built up of two main parts:
1. THE ROTOR (or Rotating Element).
2. THE CASING (or Housing or Body).

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POSITIVE DISPLACEMENT PUMPS
Positive displacement means that, when the
pump piston or rotor moves, fluid moves and
displaces the fluid ahead of it. Because of its
operation, a positive displacement pump can
build up a very high discharge pressure and,
should a valve in the discharge system be closed
for any reason, serious damage may result - the
cylinder head, the casing or other downstream
equipment may rupture or the driver may stall
and burn out.
A Positive Displacement pump must therefore be fitted with a safety relief system on the
discharge side.
Types of Positive Displacement Pump
A. ROTARY PUMPS
B. RECIPROCATING ( PISTON ) PUMPS
ROTARY PUMPS
In Rotary pumps, movement of liquid is achieved by mechanical displacement of liquid
produced by rotation of a sealed arrangement of intermeshing rotating parts within the pump
casing.

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Rotary pumps have further many types. Gear pump is one of the most commonly used types.
GEAR PUMP
In this pump, intermeshing gears or rotors rotate in opposite directions, just like the gears in a
vehicle or a watch mechanism.
The pump rotors are housed in the casing or stator with a very small clearance between them
and the casing. (The fluid being pumped will lubricate this small clearance and help prevent
friction and therefore wear of the rotors and casing).
Working
The working of the gear pump can be explained as follows:
1. In this type of pump, only one of the rotors is driven. The intermeshing gears rotate the
other rotor. As the rotors rotate, the liquid or gas, (this type of machine can also be
used as a compressor), enters from the suction line and fills the spaces between the
teeth of the gears and becomes trapped forming small 'Slugs' of fluid between the
teeth.
2. The slugs are then carried round by the rotation of the teeth to the discharge side of the
pump.
3. At this point, the gears mesh together and, as they do so, the fluid is displaced from
each cavity by the intermeshing teeth.
4. Since the fluid cannot pass the points of
near contact of the intermeshed teeth
nor between the teeth and casing, it can
only pass into the discharge line.
5. As the rotation continues, the teeth at
the suction end are opened up again and
the same amount of fluid will fill the
spaces and the process repeated. The
liquid at the discharge end is constantly
being displaced (moved forward).
Thus gear pumps compel or force a fixed volume
of fluid to be displaced for each revolution of the rotors giving the 'Positive Displacement'
action of the pump. Gear pumps are generally operated at high speed and thus give a fairly
pulse-free discharge flow and pressure. Where these pumps are operated at slower speeds, as
in pumping viscous liquids, the output tends to pulsate due to the meshing of teeth.

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RECIPROCATING (PISTON) PUMPS
A 'RECIPROCATING' pump is one with a forward and backward operating action.
It is essentially a hand operated compressor and consists of a metal or plastic tube called a
'Cylinder' inside of which a hand-operated rod or 'Piston' is pushed back and forth. On the
piston end, a special leather or rubber cup - shaped attachment is fixed.
 When the piston is pushed forward, (this is called a 'Stroke'), the cup flexes against the
cylinder walls giving a seal to prevent air passing to the other side. As the pump handle
is pushed, air pressure builds up ahead of the cup and is forced (discharged) into the tire
through the tire valve this also prevents air escaping when the pump is disconnected or
when the piston is pulled back.
 When the pump handle is pulled back, (called the 'Suction' stroke), the cup relaxes and
the backward motion causes air to pass between it and the cylinder wall to replace the
air pushed into the tire. This
reciprocating action is repeated until
the tire is at the required pressure.
Because the air is expelled from the
pump during the forward stroke only,
the pump is known as a 'Single Acting
Reciprocating Pump'. Double acting
pumps are also available.
Advantages
 Reciprocating pumps will deliver fluid at
high pressure (High Delivery Head).
 They are 'Self-priming' - No need to fill
the cylinders before starting.
Disadvantages
 Reciprocating pumps give a pulsating
flow.
 The suction stroke is difficult when
pumping viscous liquids.
 The cost of producing piston pumps is
high.
 They give low volume rates of flow
compared to other types of pump.

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HYDEL DEVELOPMENT
This section of WAPDA was established in 2010 to deal with modernization and rehabilitation of
old power stations and construction of new small power projects.
This department was needed due to the fact that with the passage of time, there is always a
demand of rehabilitation and maintenance of existing machinery. As some of our hydro electric
plants are existing before the independence of the PAKISTAN like Renala(1925), Jabban(1936)
and some after independence but still very old like Dargae(1952), Warsak(1960) etc.
There were different problems faced during the generation process, hence WAPDA established
this department for the development of these existing projects and also for construction of new
projects but of small capacity and named it as “HYDEL DEVELOPMENT” section.
The current duties of this department are as follows:
Duties
 Renovation of Mangla Power Station (Replacement of Generators)
 Rehabilitation of Mangla training Center
 Rehabilitation of Warsak Dam( Underground power house scheme with the increase
incapability to 375 MW)
 Reconstruction of Jabban Power House (Since Feb 2010 40% been completed)
 Upgardation of Renala power station (1MW to 4MW by addition of 2 M/C of 1.5 MW
capability each)
 Construction of new power stations(Bonji, Daso, Basha, Harpo, Phunder)
 Testing of new and existing electromechanical machinery
 Study and checking of feasibility documents
The brief detail of the following two current projects of this department is explained as:
 Rehabilitation of Mangla hydel power station
 Rehabilitation of Warsak hydel power station

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REHABILITATION OF MANGLA HYDEL POWER STATION
Mangla Dam Project completed in 1967 is located on River Jhelum at about 120 kM from
Capital Islamabad. The Power House was completed in four stages, the initial phase comprising
of four units of 100 MW each was completed in 1967~1969. The first extension of Units 5~6
(2X100 MW) was completed in 1974 while second extension comprising units 7~8(2X100 MW)
was completed in 1981. The project attained its maximum capacity of 1000MW with the final
extension of units 9&10(2X100 MW) in 1993-94. During high reservoir level period, Mangla is
able to generate 1150 MW against the rated capacity of 1000MW due to permissible over
loading of 15%.
Since the reservoir capacity had reduced to 4.674 MAF from 5.88 MAF due to sediment
deposition, raising of Mangla Dam by 30 ft. was taken in hand which has now completed. The
Project will provide additional water storage of 2.88 MAF, increase water head by 30 ft and
power generation of 644 GWh per annum and further flood alleviation.
In the light of increase in aforesaid parameters, WAPDA intends to carry out a Feasibility Study
for Up-gradation & Refurbishment of the old Generating Units and Allied Equipment of Mangla
Power Station to ensure their optimized, reliable and sustainable operation in the Post Raised
Mangla Dam Scenario. Electrical & Mechanical Equipment of the existing units after having
spent 30 years or more of their useful lives have deteriorated due to aging effects resulting in
reduction of efficiency and dependability.
The intended Feasibility Study is aimed to assess the present operating conditions of existing
Civil Structures & Plant Machinery, Study of various options of Refurbishment of Electrical &
Mechanical Equipment and to recommend the most viable option for Up-gradation /
Refurbishment of Power House Generating Units for achieving optimum benefits as a result of
enhanced water availability and increased head after Mangla Dam Raising.
Seven Consulting Firms/JVs were short-listed on the basis of their EOIs, invited by WAPDA for
the above Task. Requests for Proposals (RFP) were issued to short-list Consulting Firms/JVs on
05-12-2009 with last date of submission as 17th February, 2010. Six Consulting Firms/JVs have
submitted their Proposals upto the due date. Initial Technical Evaluation of these Proposals is in
process.
Total cost of the Project is roughly estimated to be US $ 300 to 500 million. However, better
Cost Estimation of the project will be available after completion of the above study. USAID has
shown interest to finance the subject Project.

37
REHABILITATION OF WARSAK HYDEL POWER STATION
Warsak Hydel Power Station is located on River Kabul at 30 KM in North – West of Peshawar.
The Project was completed under Colombo Plan under two phases and financed by Canadian
government. The first phase completed in 1960 consisted of construction of Dam, irrigation
tunnels and installation of four power generating units, each of 40 MW capacity with 132 KV
transmission system which was completed in 1960. Two additional generating units each of
41.48 MW capacity were added in 1980-81 in the second phase. The total installed capacity of
the station thus became nearly 243 MW.
WAPDA intends to carry out a Feasibility Study for Rehabilitation, Up-gradation &
Modernization of Electrical & Mechanical Equipment of Warsak Hydroelectric Power Station to
ensure its reliable and sustainable operation at the total installed capacity of 243 MW. The
Electrical & Mechanical Equipment of the existing units having spent 50 years (Units 1~4) and
30 years (Units 5~6) of their useful lives, have deteriorated due to aging effects resulting in
reduction of reliability and dependability.
The intended Feasibility Study is aimed to study and determine viable solutions and required
Works for Rehabilitation, Up-gradation and Modernization of old E&M Equipment, recommend
necessary remedial measures to overcome the defects in Civil Structures and to carry out
Sedimentation Management Studies. Further, preparation of Detail Design, Tender Documents
and PC-I for Warsak Rehabilitation Project (Phase-II) will also be a part of the required
Consultancy Services.
Seven Consulting Firms/Joint Ventures were short-listed on the basis of their EOIs, invited by
WAPDA for the above Task. Requests for Proposals (RFP) have been issued to the short-listed
Consulting Firms/JVs on 23-01-2010 with last date of submission of Proposals as 26th March,
2010.
WAPDA approached Canadian High Commission Islamabad through EAD to seek Financial
Assistance from CIDA as was done earlier for the first phase of Warsak Rehabilitation Project
(1996~2006). But CIDA showed inability to provide any funding for the proposed Rehabilitation
scheme. WAPDA then requested EAD on 22.12.2009 to approach JICA, KFW, ADB, IDB or any
other Financing Agency to provide Funds for the Subject Project.
Economic Affairs Division has forwarded above request of WAPDA to Asian Development Bank.
In response ADB demanded a Concept Note of the Project from WAPDA which is being
provided.
Approximate cost of the Project is US $ 200 to 300 million.

38
Lecture By: Manzar Hussain, Chief Engineer Hydel Development WAPDA
Outlines:
 Concept Of Magnet
 Electromagnetism Theory
 Working Principle Of An AC Generator
 Power Transmission
 Electrical Circuit Elements
 Prime Movers
 Power Generation Methods
 Types Of Motors
 Types Of Turbines
 Types Of Generators
 Transmission System
 Transformer
 Switch Yard
TRANSFORMER
 Function: It is used to step up or step down the voltage.
 Types on the basis of construction: Core Type & Shell Type
 Components:
1. Outer Body
2. Fins for air cooling
3. Core
4. Windings
5. Bushes
6. Connections (star & delta arrangement)
i. Low voltage side has star arrangement (4 connections)
ii. High voltage side has delta arrangement (3 connections)
 Dielectric: It is used for as a medium for insulation.
 Tank: The outer tank of transformer is air tight to avoid moisture contents inside. This
moisture will spoil the quality of oil. For this purpose, we use silica jel bags in the casing.
It is porous material and a good dehydrating agent. When it absorbs moisture, it turns
pink. This indication warns to replace the bag.

39
 Oil: The tank is filled with oil. Oil is the heart of the transformer. The function of oil is to
provide sufficient cooling and insulation in the two windings.
 Breathers: Nitrogen bags in the large transformers act as breathers. They are used for
breathing of transformer.
 Buckles: When these operate, the transformer trips over.
 Tapes: The connections have tolerance tapes of ±2.5% or ±5%. e.g., a 132 KV
transformer can accept 128, 130, 134, 136 KV voltages. This tape changing may be
automatic or by selector switch. Automatic tape changing is not available in small
transformers and it is off load.
Power & Distribution Transformers
Small transformers that are used by distribution companies like LESCO to supply power to
residential areas are called Distribution Transformers. They are usually step down transformers,
usually step down the voltage from 11 KV to 220 V.
Larger transformers in switch yard and grid station are called power transformers. They may be
step up or step down.
Cooling of Transformer
i. Natural Cooling (By the fins provided on the outer surface of the tank)
ii. Forced Cooling (Water is pumped into the tubes inside the tank. Hot water comes out
and fresh water is induced into the tubes for cooling.)
Rating of Transformer
The rating of a transformer is done in Volt Ampere (VA) like 25 KVA, 50KVA, 138MVA.
CT, VT & PT
a. They are placed at lines and are very helpful in measuring current, voltage and power
respectively.
e.g. a line has a current of 1 KA, it is very difficult to measure that much amount
of current directly. These transformers step down the current according to the
ratio of the windings (like 100:1 or 1000:1), the current will be reduced to 1 A.
Now, it is very easy to measure such a small amount.
b. They are also for protective measures. CT is connected to the relays. Whenever there is
a fault, the contactor opens the circuit so that whole line may not be damaged.

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HYDRO PLANNING
Hydro planning department deals with the planning of upcoming hydro electric projects of large
capabilities.
Planning of a project is quite lengthy process and according to rough estimate, about 10-12
years are required for the complete study of any project.
What is a Project?
“A project is a proposal for investment with the definite aim of producing a flow of output over
a specified period of time”
It lends itself to planning financing & implementation as a unit and it has a specific starting
point and a specific ending point intended to accomplish a specific objective
Project Cycle
A project cycle depends on the following steps:
 Identification
 Formulation
 Appraisal
 Approval
 Implementation
 Evaluation
1. IDENTIFICATION
The first and basic step of any project is to identify the resource potential area to be
selected in the upcoming project and this is done by considering the following :
 Resources Potential
 Investment Opportunities
 Socio-Economic Objectives Indicated In Plans
 Local Needs

41
 Directives
 Results Of Surveys / Investigations / Research Works
 Press Information Media
 Removal Of Constraints
 Supply-Shortage
 Restoration / Renovation / Rehabilitation / Resettlement
 Efficient Use Of Waste
The results of surveys and investigations mainly help in the identification of site for the project.
Different surveys are related to:
 Geological Investigations
 Hydrology
 Civil Structure
For the geological investigations GT Sheets are required. These sheets are basic drawings of
geological analysis made by Pakistan Survey Department (PSD). These sheets tell us about the
geological status and structures of the location.
The important data to be obtained is the availability, flow and head of water which are taken
by the fifty years back flow duration curves. (hydrology survey)

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2. FORMULATION
This step includes the study of the following aspects of the project:
 Purpose / Objectives
 Project Area
 Location
 Size
 Costs
 Funding
 Management
3. APPRAISAL
Appraisal is comparison of costs and benefits. Following are appraisal aspects:
 Economic
 Financial
 Technical
 Commercial
 Institutional
 Organizational
 Managerial
 Social
 Environmental
Importance of appraisal
To convince yourself that the project costing is worth it. To convince the approving authority
that the project being offered/proposed is worthy of implementation
Measures of project worth
 Benefit- cost ratio
 Net present worth
 Internal rate of return

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4. APPROVAL
Approval is re-appraisal for decision making.
Assumptions of undertaking the appraisal
 Life of project
 Discount rate
 Prices
Aspects of approval
 Availability of resources
 Inter-sectoral and intra-sectoral priorities
 Economic and social priorities
 Political pressure
5. IMPLEMENTATION
Conditions
It is here that you will see the impact of how well you prepared the project. For
implementation, we see the following aspects:
 How far the prevailing conditions are conducive?
 How skillfully the project is handled for execution?
 How far the project suffers from planning deficiencies?
Quality & quantity of human and material resources made available for execution of the project
with the help of above study.
6. EVALUATION
Evaluation is carried out when a part of the project is executed or completed to assess the
magnitude of gap between promise and performance.
Evaluation is the process of critically examining the areas of success and failure of projects.

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FORMS:
To remain well informed about a development project, Government of Pakistan designed
different forms for the purpose of planning, monitoring and reporting during different stages of
project cycle. These are:
 PC-II PROFORMA
 PC-I PROFORMA
 PC-III PROFORMA
 PC-IV PROFORMA
 PC-V PROFORMA
 PC-I and PC-II deal with identification and preparation of projects for implementation.
 PC- III deals with the progress monitoring of projects under planning and
implementation.
 PC-IV and PC-V deal with projects after implementation.
PC-II PROFORMA
It deals with project proposal and is required for conducting surveys (identification of
hydropower resources) and feasibility studies, in respect of large projects.
 The objective of this is to get full justification for undertaking the project before large
resources are tied up.
 It should cover general description of the aims, objectives and coverage of the study.
Previous studies in the same field should also be included.
 Duration of study and commencement/completion months is also a necessary part.
 It should contain cost estimate broken into local and foreign exchange expenditure.
 The date on which cost estimate is prepared should also be written.
 In case of foreign exchange involvement, firm commitment from sponsor may be
indicated.

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PC-I PROFORMA
It is the basic form on which all projects are required to be drawn up and it is prepared after
detailed feasibility study.
 Its preparation is the pivotal phase of the project cycle because after its approval project
implementation will be taken up.
 Detailed design and drawings are not pre-requisite for the approval and preparation of
PC-I.
 PC-I Proforma comprises three parts:
1. Part a “project digest”
2. Part b “project description and financing”
3. Part c “project requirement”
PC-III PROFORMA
This proforma is designed to furnish information on the progress of on-going projects on
quarterly basis and this is to be submitted during planning and implementation phase.
 It is required to be submitted by the executing agencies/departments within 20 days of
the closing of each quarter.
 It shall include financial as well as physical progress of the subject project.
 Information regarding bottlenecks experienced during the execution period shall also be
incorporated.
PC-IV PROFORMA
This is the project completion report and it is to be furnished by every project
director/executing agency only once, soon after a project is adjudged to be completed
physically, whether or not the accounts of the project have been closed.
The project completion report includes:
 The full history of the project including financial and physical phasing.
 Emphasising the risks taken and mistakes committed along with the remedial measures.
adopted and experience gained.
 History of the number of persons employed.

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 Suggestions about prevention of delays and cost escalation.
 Comparison of planned performance with actual performance.
 The reasons to achieve planned performance.
PC-V PROFORMA
This proforma is to be furnished on an annual basis for a period of five-years by the agencies
responsible for operation and maintenance of the projects.
PC-V proforma should include:
 The review of cost, expenditure and financial results as estimated in completion report.
 Reasons for variation in result for future guidance to planner and decision makers.
 The performance of the persons involved in operation and maintenance.
 Any difficulties experienced during operation should also be highlighted.
 Future suggestion to avoid any type of mistake.

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VISIT TO NANDIPUR POWER PLANT
Visits are always useful for engineers. They allow them to visualize the technicalities of the
projects. During our internship at WAPDA, we got an opportunity to visit Nandipur Power
Plant. This plant is of significant importance since it is producing the same power as was
estimated many years ago.
We visited Nandipur power plant on 11 July, 2012. Resident Engineer Hafiz Muhammad Jamil
received us with warm welcome and gave a comprehensive description about the plant.
INTRODUCTION
Gujranwala hydal power station Nandipur is situated at RD 44000 on upper Chenab canal near
Nandipur village at distance of about 10km from Gujranwala on Gujranwala-Sialkot road.
Upper Chenab canal takes-off from the river Chenab at Marala Head Works with full discharge
capacity of 16000 cusecs.
Nandipur Power Plant has the following specifications:
 Capacity:
The total installed capacity of Hydal power station Nandipur is 13.8MW at 0.8 power
factor consisting of 3units each having a capacity of 4.6MW.
 Discharge:
Maximum discharge in the canal is available during summer and varies considerably
during the whole year. The designed head ranges from 19.8 ft to 24.4 ft.
 Transmission:
The power house operates as base load connected to National Grid System through
66KV Gujranwala and Daska transmission lines. There is one 11KV feeder supplying
power WAPDA colony HPS Nandipur.

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STATION DATA
Unit # Date of
commissioning
Capacity
(MW)
Head
(ft)
Discharge
(cusecs)
UNIT#1 22-03-1963 4.6 22 3040
UNIT#2 26-03-1963 4.6 22 3040
UNIT#3 17-03-1963 4.6 22 3040
TOTAL 13.8 22 9120
Salient Features:
 Maximum Discharge= 10028 Cfs
 Absolute minimum Discharge= 1800Cfs
 Design water head= Max. =24.4 ft
Min.=19.8ft
 Total cost of project= Rs. 56.224 million
 Type of turbine= Kaplan turbine
 Cost Benefit Ratio= 1/1.26
 Name of consultant= M/s . Engro Project of Yugoslavia
 Source of funding= Barter
Major Components:
The major components of the power plant are:
 Turbines
 Generators
 Transformers
 Switchyard
Other areas present there are: control room, model of the plant, inlet gates and TSR.

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TURBINE
A hydraulic turbine produces prime motive power by rotating the runner connected to a shaft,
a mechanism for controlling water flow to the runner and water passages leading to the control
mechanism.
In Nandipur power house, Kaplan turbines with four numbers of blades have been installed to
obtain maximum power at low head and high discharge rate available at Upper Chenab Canal.
Technical Data:
 Output= 6500 BHP
 Design Discharge=3040 Cusecs
 Head= 22 ft
 Rate Speed= 107 rpm
 Runway speed=280 rpm
 Made by= M/S TTTOVI ZAVODI
YOGOSALAVIA
GENERATOR
In electricity generation, an electric generator is a device that converts mechanical
energy to electrical energy. A generator forces electric charge (usually carried by electrons) to
flow through an external electrical circuit.
The rotor installed in Nandipur HPS has 56 poles as per designed speed of 107 rpm by the basic
relation N=120xf/p.
Technical Data:
 Output= 3×5750 KVA
 Power factor= 0.8
 Rated current = 1010 Amp
 Voltage=3.3 KV
 Number of Poles=56
 Made By= M/S RADE KONCAR
YUGOSALAVIA

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POWER TRANSFORMER
A transformer is a device that transfers electrical energy from one circuit to another
through inductively coupled conductors—the transformer's coils.
Transformers are essential for high-voltage electric power transmission, which makes long-
distance transmission economically practical. Nandipur switchyard has two 66KV and one 11KV
transformer
Technical Data:
 Output= 2×8500 KVA
 Voltages= 11/66 KV
 Current= 446/ 74.5 Amp
 Connection =YD-5
 Impedance= 8.6 %
 Made By= M/S RADE KONCAR
YUGOSALAVIA
SWITCHYARD
A switchyard is essentially a hub for electrical power sources. For instance, a switchyard will
exist at a generating station to coordinate the exchange of power between the generators and
the transmission lines in the area. A switchyard will also exist when high voltage lines need to
be converted to lower voltage for distribution to consumers.
66KV Air Blast Circuit Breaker:
 Rated current=800 amp
 Rated pressure =14 kg/cm2
 Voltage= 66KV
 Made By= MERLIN GERIN GRENOBLE,
France
No. of Transmission Lines:
 To Gujranwala Grid (132KV)
 To Daska Grid (66KV)

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Other components observed with brief details are as below:
 In control room, there were electronically controlled systems and relays, maintaining
the generation and transmition in the station.
 At the back of generating units, there were inlet gates, installed to control the inflow of
water from canal to the turbine generating unit.
 TSR machine was installed to remove the daily trash coming with canal water flow. TSR
was working similar to a manually operated crane.
 In order to lessen the heat losses, cooling system was installed. These were oil water
cooled pipes.
 A complete designed model of power house was also shown, revealing the details of the
generation scheme.
Unit # 1 was placed there in disassembled form due to the damage of one blade of Kaplan
turbine.
Model of Nandipur generating unit

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VISIT TO IRRIGATION COLONY NANDIPUR
After visiting the Nandipur power plant, we visited the Irrigation Colony Nandipur and there we
saw the models of different existing and upcoming hydal projects.
The specifications of the models present there as a civil structures are of extreme importance
as these are used to check the feasibility of the planned projects by using the real material
present at the sites of these dams and by creating the real topology of that area. So the models
are not mere models, these are also the important testing structures.
There were many models present there. The models that we observed were:
 Bhasha Hydropower Project
 Bunji Hydropower Project (River Indus)
 Neelum Jehlum Hydropower Project
Model Of Bunji:

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Model Of Bhasha:
Model Of Neelam Jehlum:

54
VISIT TO POWER TRANSFORMER SHOP KOT
LAKHPAT
“Power Transformer Engineering Services Units” is WAPDA workshop working on repairing of
power transformers at Kot Lakhpat. We visited this workshop on 12 July, 2012. Mr. Bashir
Ahmad , a supervisor of the repairing section told us about the various transformers brought
there for repairing and brief us about the working of different sections.
Power transformers refer to those transformers used between the generator and the
distribution circuits, and these are usually rated at 220 kVA and above. Power transformers are
available for step-up operation, primarily used at the generator and referred to as generator
step-up (GSU) transformers, and for step-down operation, mainly used to feed distribution
circuits
Functions of a Transformer
The purpose of a power transformer in Switch-Mode Power Supplies is to transfer power
efficiently and instantaneously from an external electrical source to an external load. In doing
so, the transformer also provides important additional capabilities:
 The primary to secondary turns ratio can be established to efficiently
accommodate widely different input/output voltage levels.
 Multiple secondaries with different numbers of turns can be used to achieve
multiple outputs at different voltage levels.
 Separate primary and secondary windings facilitate high voltage input/output
isolation, especially important for safety in off-line applications.
Locating the fault and finding the solutions is much harder job than making a new thing,
WAPDA workshop is of special importance from the point of view of providing repairing to the
damages. Defected Power transformers from all over the Pakistan are forwarded to this
workshop for the purpose of repairing.
There are four sections in this workshop:
1) Repair Section
2) Testing Section
3) Winding section

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4) Insulation
Repair Section
Power transformers from all around the Pakistan are brought here to repair. First of all,
transformers are opened and windings are separated from the shell. Different tests are
performed in order to check the fault in core, lamination and windings etc. After finding the
faults, these are recovered by the help of other sections e.g. new windings provided by the
winding section are installed if required, oil is changed often and then it is passed through VPD
(Vapor Phase Drying) Plant for the absorption of moisture.
In this section:
 Two cranes of capacity 100 ton each are available, for more than 100 ton weight
coupled cranes are used.
 Currently they are working on a Power transformer of 250 MVA. It was damaged
because of stress stain forces on windings.

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Separation of windings for repairing
Testing Section
This section is working in collaboration with PEL (Pak Electron Limited).Power transformers of
capacity 1013MW, 2026MW and 40 MW are tested here after repairing to check the expected
accurate working of transformers before finalizing the repair procedure.
Following Quality tests are performed in this section:
 Insulation resistance
 Turn ratio
 DC winding resistance
 Capacitance and dissipation factor
 No load losses
 Power frequency tests
 Induce over voltage with
partial discharge
Oil Test Lab:
 Dielectric test
 Acidity test
 Moisture analysis
 Interfacial tension
 Viscosity
 Flash point
 Dissolved gas analysis
 Oxygen stability
 Tangent-Delta test

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Winding Section
This section deals with the making of new windings for transformers and also the repairing of
old windings for transformers. The windings which are damaged due to over heating or short
circuiting are repaired in this section and this is the special achievement of this workshop that
they are reusing the damaged copper which saves much of the cost.

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Insulation Section
The section is serving the duties of preparing the insulations for the transformers. The
insulation for transformers is basically made by highly compressed wood sheets. Due to
compression the wood proves to be an excellent insulator.
This section also deals with the transformer oil which is a very important insulation component
for the power transformers.
Finally after the complete removal of damages by installing new windings, changing insulation
sheets or some other processes, the secondary and primary windings are assembled together
with the core present in between the winding rings and connections (delta and star) are made
manually.

59
The four sections are performing their duties side by side to repair the transformers
successfully and this workshop proves itself not only economically beneficial for WAPDA but
also the only skillful transformer repairing workshop in Pakistan. That’s why Power
transformers from all around the Pakistan are brought here for the purpose of repairing.
The following image shows the transformers were present there on 12th July in repairing
process;

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VISIT TO SHALAMAR RECLAMATION SHOP
WAPDA has three transformer workshops for the repair and reclamation of distribution
transformers. These workshops are present in:
 LAHORE(SHALAMAR)
 SAKHAR
 NOSHERA
We visited the Shalamar Reclamation Workshop on 13th July, 2012. This workshop is the
biggest among the three and was built in 1977. Mr. Saleem Shams guided us about the
manufacturing, repairing and testing of distribution transformers.
Distribution transformers are used to convert higher voltage (usually 11-22-33kV) of the
electric distribution system, to a lower voltage (250 or 433V) needed at the customers end with
frequency identical before and after the transformation. With given secondary voltage,
distribution transformer is usually the last in the chain of electrical energy supply to households
and industrial enterprises.
It is basically a static device constructed with two or more windings used to transfer alternating
current electric power by electromagnetic induction from one circuit to another at the same
frequency but with different values of voltage and current.
Construction
There are 3 main parts in the distribution transformer:
1. Coils/winding – where incoming alternate current (through primary winding) generates
magnetic flux, which in turn develop a magnetic field feeding back a secondary winding.
 The low current, high voltage primaries are
wound from enamel coated copper wire.
 The high current, low voltage secondaries are
wound using a thick ribbon of aluminum or
copper insulated with resin-impregnated paper.

61
2. Magnetic core – allowing transfer of magnetic field generated by primary winding to
secondary winding by principle of magnetic induction.
 Core is made from laminations of sheet steel stacked and either glued together with
resin or banded together with steel straps.
3. Tank – serving as a mechanical package to protect active parts, as a holding vessel for
transformer oil used for cooling and insulation and bushing (plus auxiliary equipment
where applicable)
 The entire assembly is baked to cure the resin then submerged in a large (usually
gray) powder coated steel tank which is then filled with high purity mineral oil, which is
inert and non-conductive.

62
The above mentioned parts are manufactured and repaired in this workshop. The different
sections are performing the following duties:
 Winding section is performing their duties of repairing and manufacturing of new
windings. Actually, the insulation of copper wires by covering them with the three layers
of special Press Pond paper is done in this section.
 After the proper insulation of the copper wires, windings of the transformer are
constructed with sufficient turns in each winding to limit the no-load or exciting current.
The voltages induced in each turn of the primary and secondary winding coils will be
approximately equal, and the voltage induced in each winding will be equal to the
voltage per turn multiplied by the number of turns.
These windings are then checked for correct or desired turn ratio by completing the
loop through the TTR machine.
TTR machine Connection with poles
 The core is then made up by arranging the steel plates of specific design in particular
positions as per the core design. Then the windings are installed with the core plates in
between them.
 Finally the connections of windings are made with the poles of transformer by the star
and delta arrangements.
 After baking the whole assembly, it is submerged in the oil filled tank and passed
through IRON and COPPER losses test before finalizing the manufacturing process.

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STANDARDS
 IRON and COPPER losses
Capacity of transformer IRON losses with 15% COPPER losses with 15%
25KVA 141W 736W
50KVA 201W 1346W
100KVA 356W 2323W
200KVA 570W 3922W
 Quantity of oil used in transformers:
Capacity of transformer Qty of oil in liters
25KVA 80
50KVA 120
100KVA 180
200KVA 300
 Weight of the paper covered copper strip used in L.T winding:
Capacity of transformer Size Weight in KG
25KVA 3x4 15
50KVA 5x4 25
100KVA 5x8 35
200KVA 5x8 55

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 Weight of the enameled copper wire used in H.T winding:
Capacity of transformer Size Weight in KG
25KVA 0.6 25
50KVA 0.8 35
100KVA 1.1 55
200KVA 1.5 80
Sample Tests
The Quality up Gradation tests performed are:
1. Windings Resistance Test
2. No Load Test
3. Full Load Test
4. Induced Voltage Test
5. Separate Source Over Voltage Withstand Test
6. Turn Ratio Test
7. Air Pressure Test
8. Bird Protection Test
9. Tin Coating and other Allied Test on Connector
10. Visual and Dimensional
11. Oil test of transformer
Transformer Oil
Transformer working totally depends upon insulation. Mineral oil is used as the transformer oil
which helps dissipate heat and protects the transformer from moisture, which will float on the
surface of the oil.
This workshop has a separate oil section and is working successfully in improving the quality of
transformer oil by processing it through the following tanks.
 Agitator Tank (6hr)
 Cleansing Tank (Neutralization using NaOH)
 Filter Press
 Decantation Tank (12-13hr)

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The oil quality tests standards as per IEC-296 are;
Specific gravity at 20°C <0.895/cm3
Acidity Neutralization 0.03ma KOH/g of oil
Viscosity at 20°C < 40°C
Flash Point >140°C
Pour point(Freezing Point) <-30°C
Moisture contents <30ppm
Dielectric Strength >30KV
Tangent Delta <0.005
Corrosive sulphur Non-corrosive
The above standard values are achieved at any cost for the efficient and deigned performance
of the transformer.

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FINANCE DEPARTMENT
The finance e department deals with all the financing and managing of finance related activities
for the distribution of money, funds and investments required for the smooth running of
current and upcoming projects. This also deals with how to take taxes and preparation of
balance sheets, income statements and other related issues.
In WAPDA Finance department basically deals with the following 2 sectors:
 Operations and Maintenance
 Development
Finance department is working according to WAPDA ACT introduced in 1958. This department
is purely based on law of economics which includes cost benefit analysis. The projects are
processed on the basis of DEBT EQUITY RATIO which is 80:20 respectively. In this ratio Debt
consists of GOP Grants, GOP Loans, Donor Agencies and WAPDA owned sources while equity is
SELF FINANCING.
Regarding the costs every project is approved from the GOP. If cost of a project exceeds after a
delay then approval is required once again from GOP.
According to GENERATION LICENSE 2004, NEPRA issues licenses to generation, transmission
and distribution sector.
Restructuring of WAPDA
WAPDA was restructured into 14 companies and residual WAPDA in 1998.
SECP (Security Exchange Commission of Pakistan) approves the registration of new companies.
These registered companies use: CO (company) at the end of their names.
There are 3 types of companies:
 Public Limited
 Private Limited
 Guarantee Limited (STOCK EXCHANGE OF PAKISTAN)
14 COMPANIES THAT WERE RESTRUCTURED INTO:
 4 generation companies (GENCOS)
 9 distribution (DISCOS)
 1 NTDC

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GENCOS
1. JAMSHORO POWER COMPANY Limited (JPCL) GENCO I
2. Central Power Generation Company Limited (CPGCL) GENCO II
3. Northern Power Generation Company Limited (NPGCL) GENCO III
4. Lakhra Power Generation Company Limited (LPGCL) GENCO IV
DISCOS
 TESCO: Tribal Electric Supply Company
 PESCO: Peshawar Electric Supply Company
 IESCO: Islamabad Electric Supply Company
 LESCO: Lahore Electric Supply Company
 FESCO: Faisalabad Electric Supply Company
 GEPCO: Gujranwala Electric Supply Company
 MEPCO: Multan Electric Supply
Company
 SEPCO: Sakhar Electric Supply
Company
 HESCO: Hyderabad Electric Supply
Company
 QESCO: Quetta Electric Supply
Company
 KESCO: Karachi Electric Supply
Company
CPPA
Central Power Purchase agency purchases energy from all energy generating sources of
Pakistan. Then sales the energy to DISCOS and DISCOS further distribute the energy to the
consumers at a diversified tariff which is decided by NAPRA. All generation sources sale their
energy to CPPA at the estimated price. After that CPPA sale that energy to DISCOS and NEPRA
decides the most appropriate tariff for the DISCOS.
Calculation of Revenue
1. Operation and Maintenance
2. Depreciation
3. NHP (Net Hydal Profit)
4. WUC (Water Usage Charges)

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5. ROA (Return on Assets)
VISIT TO AC PLANT IN WAPDA HOUSE
Our first meeting was with XEN, AC Plant in 311-WAPDA house. The discussion was primarily
about the HVAC systems.
There are two basic HVAC systems
A. Vapor Absorption System
B. Vapor Compression System
In WAPDA house, Vapor Absorption Cycle is used in the Plant for the purpose of building air-
conditioning.
Air-Conditioning of Large Buildings
To condition the larger buildings, it is economical to use AC plant instead of small window units.
In a large building of seven storeys and a basement with less or more 800 rooms, like in WAPDA
House, it is very expensive to have separate ducts for each unit. Moreover, the building would
have over-fixture view. To have a comfortable environment in the building, we prefer to have
an AC plant.

69
Absorption Chiller Systems
The chiller systems are of three types basically:
1. Water Cooled System
a) Smaller units
b) Multi-chiller
c) Multiple cooling towers
d) Compact size
e) Instant cooling
f) Less running expenditures
2. Air Cooled System
a) Comparatively large units
b) Multi-chiller with multiple circuits
c) Comparatively large cooling towers
d) Size depends upon the size of the building
e) Delay cooling
f) High operating costs because of chemicals
3. Gas Absorption System
a) Bigger Units (1 or may be 2 units as per requirement)
b) Large cooling towers
c) Large space required
d) Slow cooling (at least half an hour is required for proper air-conditioning after the
running on of the plant)
e) Consumption of gas and chemicals
f) High operating cost
g) Needs a boiler
h) Efficient for conditioning of large buildings

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Working Principle of Absorption Cycle
HIGH PRESSURE SECTION
Concentrator and Condenser
Steam or hot water moving through the concentrator tube causes the LiBr to boil. The
refrigerant, water is liberated from the LiBr as it boils. The refrigerant vapor then passes
through an eliminator section that separates the concentrator from the condenser. The
eliminators remove droplets of LiBr from the vapor as it passes to the condenser. Water flowing
through the condenser tubes cools the refrigerant vapor as it passes into the condenser .this
causes the vapor to condense. The condensed refrigerant falls to condenser pan and is directed
into the evaporator section through several pipes which terminate at an orifice. As the
condensed refrigerant passes through the orifice into the lower pressure evaporator section, a
portion flashes to vapor, causing the temperature of the remaining liquid refrigerant to drop.
LOW PRESSURE SECTION
Evaporator and Absorber
The heat from the system chilled water is used to vaporize the refrigerant at approximately 40 F
in the evaporator section. As the refrigerant changes state, heat is removed from the system
water. The resulting water vapor is then drawn into the relatively lower pressure absorber
section and is absorbed into an aqueous solution of LiBr. Cooling water is circulated through the
absorber tube bundle in order to remove the heat of dilution from the LiBr solution. The LiBr
that is sprayed over the absorber tubes absorbs the refrigerant water vapors and then becomes
diluted, reducing its ability to absorb. Therefore, it is necessary to return the dilute solution to
the concentrator to reclaim the refrigerant.
SOLUTION HEAT EXCHANGER
Dilute Solution is pumped to the concentrator, but first passes through a heat exchanger. The
heat exchanger’s function is to efficiently exchange heat between the hot concentrated and
cool dilute solution. During operation, the heat exchanger transfers heat between the cool
dilute LiBr solution from the absorber and the hot concentrated solution being returned from

71
the concentrator to the absorber spray trees. Dilute solution passes through the tubes of the
heat exchanger and the strong solution through the shell side around the tube. The heat
exchanger is very important to the overall efficiency of the absorption cycle.
Crystallization
During normal operation, the absorber solution concentration adjusted automatically by the
machine as needed to provide proper evaporator leaving water temperature. The condensable
are present in the absorber, the machine provide the evaporator water temperature. As a
result, the machine will continue to increase solution concentrations in order to correct this
condition. Eventually, the concentrations increase until the solution crystallizes. Normal
solution flow in the heat exchanger is then disrupted and corrective action is required. Periodic
machine purging is required to prevent this condition.
Purge System
The purge system consists of pick-up tubes and a purge chamber which are located within the
absorber. The chamber is an enclosure which isolates the section of absorber tubes. It is
connected to vacuum pump through a manual shut off valve mounted on the outside of the
machine.
Purge Pump
It is a mechanical, rotary, oil sealed, vane type, low volume unit of two-stage construction. It is
capable of operating with very low suction pressures. The pump compresses the non-
condensable gases as they are removed from the purge chamber. The compressed gas is then
discharge to the atmosphere.
AC PLANT- GENERAL INFORMATION
The Trane Single Stage Absorption Cold Generator® is designed to use 12 or 14 psig steam, or
hot water up to 270 F.
Working Fluids
 Lithium Bromide as an absorbent
It is used because it has excellent affinity for water vapor, release refrigerant vapor at
relatively low temperature and has a very high boiling point.
 Water as refrigerant

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It is an excellent refrigerant because it boils easily at a low evaporation pressure, has a
relatively high refrigeration effect.
Components
Each machine has four internal sections:
A. Concentrators
B. Condensers
C. Evaporators
D. Absorber
Additional components include:
1. Heat Exchanger
2. Electric Control Panel
3. Pneumatic Control Panel
4. Operating Valves
5. Solution Pump
6. Purge Pump
Technical Data
I. Boilers: 2 (Fire Tube Boilers)
II. Chillers: 2
III. No. of chilled pumps: 6
IV. No. of booster pumps: 3
V. Refrigerant: Water
VI. Absorbent: Lithium Bromide
VII. Capacity: 750 tons
VIII. Fuel for boiler: gas/ furnace Oil
IX. Gas Pressure: 12 psi
X. No. Of Cooling Towers: 8
XI. Length of cooling tower: 14 ft
XII. Total no. of AHUs (Air Handling Unit) : 38
a. Filters
b. Damper
c. Cooling coil
d. Blower

73
Boiler Chiller
Honey Comb structure in Cooling Tower Fan in cooling tower
Nozzles in Cooling Tower

74
ELEVATOR IN WAPDA HOUSE
WAPDA House is a multi-storey building with eight floors and basement. For comfortable
movement inside the building, it has a good lifting system. The system has been installed in
1965 when WAPDA House was erected.
There are two control rooms, one is three cars side and the other is four cars side.
There are eight cars in the elevator section. These cars move in a well. Seven cars are used for
persons and the eighth one is the service lift.
The parts which were shown on opening the elevator section are:
i. counter balance
ii. beam
iii. pulleys
iv. ropes
v. motor (for opening & closing of door)
vi. car/cabin
The control room has:
i. relay system
ii. selector switch
iii. differential gear
iv. rack & pinion
v. sheave (a wheel on which there are six V
shape grooves are mend for ropes)
vi. ropes
Technical Data
Load = 3500 lbs
Ultimate strength per rope = 22,000 lbs
Length of rope = 139-140 ft
Speed = 300ft/min
System Requirement for operation = 400 V, 114 Amp

75
Nomenclature
WAPDA: Water And Power Development Authority
PEPCO: Pakistan Electric Power Company
NTDC: National Transmission And Dispatch Company
DISCO: Distribution Company
TESCO: Tribal Electric Supply Company
PESCO: Peshawar Electric Supply Company
IESCO: Islamabad Electric Supply Company
LESCO: Lahore Electric Supply Company
FESCO: Faisalabad Electric Supply Company
GEPCO: Gujranwala Electric Supply Company
MEPCO: Multan Electric Supply Company
SEPCO: Sakhar Electric Supply Company
HESCO: Hyderabad Electric Supply Company
QESCO: Quetta Electric Supply Company
KESCO: Karachi Electric Supply Company
GENCO: Generation Company
IPPs: Independent Power Producers
KAPCO: Kot Addu Power Company
NEPRAH: National Electric Power Regularity Authority
IRSA: Indus River System Authority
NPCC: National Power Control Center
CPPA: Central Power Purchase Analysis
SECP: Security and Exchange Commission of Pakistan
IRR: Internal Rate of Return
EPP: Energy Purchase Price
CPP: Capacity Purchase Price
RSO: Residual Furnace Oil
HSD: High Speed Diesel

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