Internship saad

Internship Report 2015

Internship Report Internship at

Kapko Power Plant, District

Muzzafarabad

From 22 July 2015 to 4 Sep 2015

____________________________________

By

Muhammad Saad Qureshi

National University of Sciences and Technology

(NUST), Islamabad


Dedicated to my loving Parents

Without whom my world is empty


Introduction:

An internship is an integral part of every engineering field as it

provides the students with an opportunity to gain practical knowledge pertinent to

their field. What they learn theoretically can actually be seen being implemented

practically. This not only aggrandizes their theoretical concepts, but also serves as

a means of amplifying their knowledge. For students of electrical engineering,

working in a power plant as an intern can be of immense use. They can see for

themselves the production of electricity which is the core item of their field.

Description of the Plant:

KAPCO is Pakistan's largest Independent Power Producer (IPP) with a nameplate

capacity of 1600 MW. KotAddu Power Plant (the "Power Plant") was built by the Pakistan

Water and Power Development Authority ("WAPDA") in five phases between 1985 and 1996 at

its present location in KotAddu, District Muzaffargarh, Punjab. In April 1996, KotAddu Power

Company Limited ("KAPCO") was incorporated as a public limited company under the

Companies Ordinance, 1984 with the objective of acquiring the Power Plant from WAPDA. The

principal activities of KAPCO include the ownership, operation and maintenance of the Power

Plant.

The Power Plant is a multi-fuel gas-turbine power plant with the capability of using 3

different fuels to generate electricity, namely: Natural Gas, Low Sulphur Furnace Oil and

High Speed Diesel to generate electricity. The Power Plant is also the only major plant in

Pakistan with the ability to self-start in case of a country wide blackout

On June 27, 1996, following international competitive bidding by the Privatization

Commission, Government of Pakistan (the "Privatization Commission"), the management of

KAPCO was transferred to National Power (now International Power) of the United Kingdom,

which acting through its subsidiary National Power KotAddu Limited (NPKAL), bought shares

representing a 26% stake in KAPCO. Later, NPKAL bought a further 10% shareholding in

KAPCO increasing its total shareholding to 36%.The other majority shareholder in KAPCO is

WAPDA with a present shareholding of 46%.

Following the successful completion of the offer for sale by the Privatization

Commission (on behalf of WAPDA) in February 2005, 20% of KAPCO’s shareholding is now

held by the General Public. On April 18, 2005 KAPCO was formally listed on all three Stock

Exchanges of Pakistan.


The Power Plant is situated in District Muzaffargarh, Punjab, 90 K.M. North west of

Multan on the left bank of the River Indus at a distance of 16 K.M. From Taunsa Barrage. The

area is surrounded by agricultural land on the north and west side of KotAddu.

Vision Statement To be a leading power generation company, driven to exceed our shareholders'

expectations and meet our customer’s requirements.

Mission Statement

To be a responsible corporate citizen

To maximize shareholders' return

To provide reliable and economical power for our customer

To excel in all aspects relating to safety, quality and environment

To create a work environment which fosters pride, job satisfaction and equal

opportunity for career growth for the employees?

Plant General Characteristics

Gas Turbines 10

HRSGs 10

Steam Turbines 5

Installed Capacity 1600MW

Max. Load Generation 1541MW

Load According to IDC Test (1996) 1345MW

Load According to ADC Test (2010) 1355MW

No. of Feeders 6 x132KV; 6 x220KV


Max. Generation in one day 35,667Mwh

KAPCO GAS TURBINE POWER STATION

KAPCO 1600MW

Block 1 Energy Block

3

SIEMENS GERMANY

GT 1

STG 9

GT 2

FIAT

ITALY

GT 3 GT 4

STG 10

Block 2 Energy Block 2

ALSTHOM FRANCE

GT 5,6

STG 11

GT 7,8

STG 12

Block 3 Energy Block 1

SIEMENS GERMANY

GT 13,14

STG 15


Description Of All Blocks

There are total three blocks in KAPCO. And there details are given below.

Block-I:

Block I is outfitted with six turbines altogether. In which four are Gas Turbine (GT1, GT2, GT3

and GT4) and other two are Steam Turbines (STG 9, STG10). The entire framework is in light of

the consolidated cycle.

GT1 and GT2 are German made and are fabricated by Siemens Engineering Co. Ltd. They have

a general warm effectiveness 28% and having an appraised limit of 100MW. Evaluated velocity

is 3000rpm. GT3 and GT4 are Italian made and are produced by Fiat Engineering Co. Ltd. They

have a general warm effectiveness 28% and having an appraised limit of 100MW. Appraised rate

is 3000rpm.

Steam Turbines (STG 9, STG 10) are produced by ABB. As there is not any sort of compressor

which utilizes around 60% vitality of GT, so its productivity is expanded up to half.

BLOCK 2:-

In Block-II there is additionally the same development of machines, yet they are all made of

ALSTHOM. Their rating and effectiveness is same as that of the block I. Every one of these

machines are synchronized straightforwardly to the transport bar, i.e. at 220 KV to connect with

transport bar.

BLOCK 3:-

Block III is furnished with three turbines altogether. In which two are Gas Turbine (GT13,

GT14) and another is a Steam Turbine (STG 15). Gas Turbines GT13, GT14 and STG 15 are

German made and are produced by the Siemens building Co. Ltd. They have a general warm

proficiency 45% in consolidates cycle mode.

Operations and Maintenance (O&M):


The O&M of the plant is divided into various sections such as:

Electrical

Mechanical

Instrumentation & Control (I&C)

Equipment & Storage

Brayton Cycle:

Brayton cycle is an idealized cycle that describes the working of a constant

pressure heat engine. Gas turbine engines and jet engine work on Brayton cycle. A Brayton-type

engine uses three components:

Compressor

A Mixing Chamber (Combustor)

An Expander (Expansion Turbine)

Ideal Brayton Cycle:

1. Isentropic process - ambient air is drawn into the compressor, where it is

pressurized.

2. Isobaric process - the compressed air, then runs through a combustion

chamber, where fuel is burned, heating that air—a constant-pressure

process, since the chamber is open to flow in and out.

3. Isentropic process - the heated, pressurized air, then gives up its energy,

expanding through a turbine (or series of turbines). Some of the work

extracted by the turbine is used to drive the compressor.

4. Isobaric process - heat rejection (in the atmosphere).

Actual Brayton Cycle:

1. Adiabatic process - compression.

2. Isobaric process - heat addition.

3. Adiabatic process - expansion.

4. Isobaric process - heat rejection.

http://en.wikipedia.org/wiki/Isentropic_process

http://en.wikipedia.org/wiki/Isobaric_process

http://en.wikipedia.org/wiki/Adiabatic_process


Brayton Cycle

Rankine Cycle:

Rankine Cycle is a model that is used to describe the working and performance of

steam engines. It describes the process by which steam operated heat engines commonly found

in thermal power plants generate power. The heat sources used are nuclear fission or combustion

of fossil fuels like coal, gas, furnace oil etc.

There are 4 processes in Rankine Cycle:-

Process 1-2: The working fluid is pumped from low to high pressure. As the fluid is a

liquid at this stage, the pump requires little input energy.

Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure

by an external heat source to become a dry saturated vapor.

Process 3-4: The dry saturated vapor expands through a turbine, generating power. This

decreases the temperature and pressure of the vapor, and some condensation may occur.

Process 4-1: The wet vapor then enters a condenser where it is condensed at a constant

pressure to become a saturated liquid.

Efficiency Improvement:

The efficiency of a Brayton Engine can be improved by:

http://en.wikipedia.org/wiki/Turbine

http://en.wikipedia.org/wiki/Surface_condenser

http://en.wikipedia.org/wiki/Boiling_point


Regeneration:

In this method the still warm post-turbine fluid is passed through heat

exchangers to pre-heat the fuel entering the combustion chambers. This decreases the fuel

consumption for the same operating conditions.

Co-generation:

In this system, the exhaust heat from the Brayton engine is used for

other useful means like hot water production, heating neighboring building etc.

Combined Cycle:

A gas turbine operates in Brayton Cycle whereas a steam turbine operates on

Rankine Cycle. The efficiency of a gas turbine is somewhere around 35%,but it can be increased

to 60% or so if Combined Cycle configuration is used. In a combined cycle, the exhaust gases

from the gas turbine are used in Heat Recovery Steam Generator (HRSG) to convert water to

steam in order to run a steam turbine. The steam, after running the turbine, is condensed to water

in a condenser and is supplied back to the HRSG. Cold water, used to condense the steam in the

condenser, circulates between the cooling towers and the condenser.

Schematic Diagram of a Combined Cycle Power Plant

Safety Policy:

Safety is the first priority of GE and great stress is laid on

observing safety rules. The Company tries its best to make the environment of the

plant safe and secure. For this purpose, safety signs and instructions are exhibited


in various places. The workers are educated and trained to work safely. Even we,

the internees, had to pass through the procedure of safety induction after which we

were allowed to visit the plant. In the safety induction, we were educated about the

importance of Plant Protection Equipment (PPE). We were also briefed about how

to react in case of an emergency. The primary PPEs without which nobody was

permitted to enter the premises of the plant are:

Safety shoes

Helmet

Goggles

In addition to these, ear plugs are necessary for the people working in noisy areas.

Water Treatment Plant (WTP):

Demineralized water, also known as the Demin Water is used in

the plant operation for various purposes. Water is treated to remove the dissolved

salts which will otherwise affect the boiler and turbine in various ways. The

presence of salts also increases the boiling the boiling point of water. But the main

problem is that as the water changes to steam in the boiler, the left behind salts can


badly damage the boiler and if they somehow reach the steam turbine, they can

cause serious damage to the blades of the turbine. Therefore, water needs to be

treated before it can be used to run the steam turbine. Demin water is not used in

HRSG but also has its utility in gas turbine for other purposes that will be

discussed later.

Steps of Treatment:

Raw water

Double media filter

Activated carbon

Reverse osmosis (RO)

Chemical treatment

Demin water

The Generator:

Synchronous generator is utilized to change over mechanical vitality into electrical vitality.


Essential Working guideline:

As indicated by Faraday's law of electromagnetic incitement:

"On the off chance that there is a relative movement in the middle of a conductor and

attractive field, then an EMF will be incited into the conductor".

To make this relative development, it doesn't make a difference whether the magnet is pivoted

and the conductor is stationary or the conductor is moving and magnet is stationary.

The greatness of the affected EMF is straightforwardly relative to the No of conductors (N) and

the rate of progress of attractive flux crossing the conductors.

Emf = N (dΦ/dt)

Different Parts of Generator:

Generally a generator consists of following parts:

Stator

Rotor

Excitation system

Carbon brushes and Slip rings

Retaining rings

Bearing


Rotor grounding system

Cooling system

Excitation system:

The excitation framework is to supply the immediate current to the rotor which permits the

generator to keep up a controlled voltage between its terminals when joined with the system. A

voltage controller drives the excitation framework. The excitation power for the generator is

supplied by an exciter with pivoting diodes that are fitted to the end of the principle generator

shaft.

Generator cooling system

The warmth misfortunes emerging in the generator inside are scattered to the optional coolant

(cooling water) through the air. Direct cooling of rotor uproots problem areas and differential

temperature between the neighboring parts. Circuitous cooling is utilized for stator winding. Air

and hydrogen are two cooling media for the generator cooling. In KAPCO all generators are air

cooled.The advantages of the air cooling system are: lower cost price,short inspection and easy

maintenance.

Cooling air is coursed in the generator by two hub stream fans on the rotor shaft. Chilled air is

drawn by fans from cooler and afterward separated into three sections:rotor section,stator and

last air gap section.

Generator Protection:

There are diverse sorts of deficiency can happen onto the generators so the security of these

flaws to the generators we utilized a few insurances. These are given underneath.

Negative phase sequence protection.

Rotor earth fault protection.

Loss of excitation.

Reverse power protection.

Differential protection.

Under frequency/over frequency relay.


Stator over current protection.

Stator over voltage protection.

Transformer:-

The transformer is a gadget that exchanges electrical vitality starting with one circuit,then on to

the next by attractive coupling without obliging relative movement between its parts. It for the

most part contains two or more coupled windings, and, by and large, a center to focus attractive

flux. A rotating voltage connected to one winding makes a period,fluctuating attractive flux in

the center, which incites a voltage in alternate windings.

TRANSFORMER TYPES:

Transformers are built so that their qualities coordinate the application for which they are

planned. The distinctions in development may include the extent of the windings or the

relationship between the essential and auxiliary windings. Transformer sorts are additionally

designated by the capacity the transformer serves in a circuit, for example,

Distribution Transformer

Start-up Transformer

Auxiliary Transformer

Auto Transformer

Matching Transformer

Isolation Transformer

Instrument potential Transformer

Isolation transformer.

Instrument current Transformer

According to cooling media:

They are classified as,

Dry (Air-cooled):

These are used according to the environment temperature and heat dissipation. They are less

expensive and they require less maintenance. Its main disadvantage is that its output rating

decreases by 1amp with an increase of one ˚C temperature.


Oil type:

These transformers have following types, having oil as a cooling medium

Unit Transformer:

Unit transformers are utilized as a part of a wide range of sorts and applications. Unit

transformers are utilized oil cooled. Here unit transformers are utilized for overwhelming

obligation. Obstruct 2 Unit transformers have the capacity to change over 11kv into 220kv.Unit

Transformers take the voltage from assistant transformers and after that pass it to the switchyard.

Obstruct 2 has Alsthom CGEE transformer made in Italy.

Start-up Transformer:

KAPCO has the capacity of self-begin. There are two start-up transformers.The start-up

transformer is utilized to venture down the voltage. Here in KAPCO they are utilized to venture

down 132KV to 11KV and stimulate 11KV transport bar. To begin with a transformer is joined

with unit 1 and 2 while the second transformer is associated with unit 3 and 4. All units of

KAPCO are interconnected start-up transformer of the unit 1and 2 can give supply to unit 5and

6 comparatively start-up transformer of unit 3 and 4 is joined with unit 7 and 8. Obstruct 3 units

can get supplies from units 5 to 8.

Auxiliary Transformer:

They are exceptionally used to make a supply of unit stable,they take 11kv from the unit and

transformer it to unit transformer and to 11kv transport bar. The yield voltage of the unit can unique in

relation to correct 11kv, which can be 10.8KV or something so these transformers are utilized to stable

this quality.

Auto Transformer:

The autotransformer is for the most part utilized as a part of low power applications where a variable

voltage is needed. The autotransformer is a unique sort of force transformer. It comprises of one and

only winding. By tapping or interfacing at specific focuses along the winding, distinctive voltages can be

acquired. Just switchyard of 132kv has four autotransformers, which has the capacity to change over

132kv into 220kv they likewise change over, 220kv into 132kv.They are similar to interconnection

somewhere around 132kv and 220kv.

Matching Transformer:

It is used for CT to make the voltage equal on both sides o f the transformer. They have a smaller

size.

Instrument Potential Transformer(PT):

The instrument potential transformer (PT) ventures down voltage of a circuit to a low esteem that can

be viably and securely utilized for the operation of instruments, for example, ammeters, voltmeters,


Wattmeters, and transfers utilized for different defensive purposes. They are utilized for Measuring

,Control ,Protection.

Instrument Current Transformer (CT):

The instrument potential transformer (PT) endeavors down voltage of a circuit to a low regard

that can be feasible and safely used for the operation of instruments, for instance, ammeters,

voltmeters, Wattmeters, and exchanges used for distinctive protective purposes. They are used

for Measuring,Control,Protection.

Control Transformer:

Control transformers are generally used in electronic circuits that require constant voltage

or constant current with a low power or volt-amp rating. Various filtering devices, such

as capacitors, are used to minimize the variations in the output. This results in a more

constant voltage or current.

Distribution Transformer:

They are by and large utilized as a part of electrical force circulation and transmission systems.

This class of transformer has the most elevated force, or volt-ampere evaluations, and the

highest continuous voltage rating. The force rating is typically dictated by the sort of cooling

methods the transformer may utilize. Some usually utilized strategies for using so as to cool are

oil or some other warmth directing material. Ampere rating is expanded in a dissemination

transformer by expanding the span of the essential and optional windings; voltage appraisals

are expanded by increasing the voltage rating of the protection utilized as a part of making the

transformer.

Energy losses in Transformer:

A perfect transformer would have no vitality misfortunes, and would in this manner be 100% proficient.

Regardless of the transformer being amongst the most productive of electrical machines, with

exploratory models utilizing superconducting windings accomplishing efficiencies of 99.85% vitality is

dispersed in the windings, center, and encompassing structures.

Losses in the transformer arise from:


Winding resistance, Hysteresis losses,Eddy currents,Mechanical losses

Transformer Protection:

Protection are essential for electric gadgets, which shield them from annihilating and make them

more sheltered to utilize. They additionally have significance for specialists wellbeing. Bigger

things have a larger number of insurances than littler things.

For security reason there are two primary Operations;

Alert, Tripping

Alert:

Alert demonstrates the discriminating circumstance of parts. Caution will ring when a gadget

achieves its discriminating quality. It additionally demonstrates evidence in CCR.

Tripping:

Tripping is the following stride of caution. At the point when the machine or gadget don't work

on its standard working,then after sensible time breaker makes the defective part disengage and

safe the transformer.

There are essentially two sorts of insurance for a transformer.

Electrical

Non Electrical

Nonelectrical Protections:

Warm Protection

Weight Protection

Level Protection

Warm Protection:

Warmth can be created because of flash,hot climate and high voltage in substantial obligation

transformer. Mercury is accustomed to ring alert and for stumbling. At the point when the

transformer is warmed, mercury is moved from Pocket and works protection.To safe the

transformer we have two most imperative operation alert and tripping.

Weight Protection:


Weight Relief worth is for body security. If there should arise an occurrence of starting oil is

warmed up and can harm the group of transformer . The quality discharge the weight that is

fabricated inside the body.

Level Protection:

Oil level abatements with the increment of temperature. On lessening of oil Alarm will ring,

however oil level security has no stumbling choice. As oil has basic reason for cooling so it is

vital to keep up the oil level.

Buchholz Relay Protection:

It is used for protection of oil filled transformer having low level of oil. This relay is installed between the

transformer tank and conservator. The minor faults in the transformer tank below the oil level actuate a

Buchholz relay so as to give an alarm

Electrical Protections:

High Voltage Protection

Over-Fluxing Protection

Earth Fault Protection

Differential Protection

Restricted Earth Fault Protection


THE BATTERY ROOMS

Reason:

The reason for the battery room is to give DC supply expected to the transfer action(mostly for

insurance purposes).

They are likewise wellspring of excitation if there should arise an occurrence of power outage crash have

crucial utilization as DC reinforcement supply.

BATTERY ROOMS:

A battery room is a room in a facility used to house batteries for backup or

uninterruptible power systems.

They are of the two sorts regarding yield voltage.

Output voltage of 48V

Output voltage of 220V.

They are of driving corrosive sort having sulfuric corrosive (H2SO4) as the

electrolyte.

Basic Principle of Battery:-

The basic principle of the battery properly, first, we should have some basic

concept of electrolytes and electron affinity. Actually, when two dissimilar metals

or metallic compounds are immersed in an electrolyte, there will be a potential

difference produced between these metals or metallic compounds.

https://en.wikipedia.org/wiki/Battery_(electricity)


SWITCHYARD

The switchboard is a place to import/export electricity. KAPCO has two switched

of 132 KV and 220 KV.

Switchyard of 132 KV:

First feeder goes to INDUSTRIAL ESTATE MULTAN.

Second feeder goes to MUZAFFARGARH-1

Third feeder goes to GUJRAT SOUTH

Forth feeder goes to D.I.KHAN-1

Fifth feeder goes to D.I.KHAN-2

Sixth feeder goes to KOT ADDU

This switchyard has a single transmission plan. This plan is not exceptionally

powerful in a bad situation in light of the fact that it can totally dead the line and

we don't have standby way. It contains 2 transport bar of 132KV and BAYS from 4

to 22. From switchyard of 132 KV 6 transmission lines go to different parts of the

country. BAY 18 and 20 are joined with autotransformer which change over 132

KV into 220 KV.BAY 6 and 17 are associated with startup transformer they

change over 132KV into 11KV GT 1,2,3 and 4 are joined with BAY 4,5,16 and 19

individually. While ST-9 and ST-10 are associated with BAY 7 and 15 separately

Switchyard of 220KV:

It contains two bus bars and BAYS from 1 to 14. This yard has one and half plan

of breakers in which we have a standby way to proceed with our transmission with

no trouble. All out 12 feeders go out from the KAPCO six feeders are 220KV and

six are 132KVA.

The subtle element of six feeders of 220KV is given beneath.

From bay 1 feeder goes to MUZAFFAR GARH

From bay 2 feeders goes to AES PAKGEN


From bay 6 feeders goes to VEHARI

From bay 7 feeders goes to NEW MULTAN 6

From bay 13 feeder go to NEWMULTAN 3

From bay 14 feeder go to NEWMULTAN 4

After stride up, the 220 KV yield from the generator transformer is encouraged to

both of the two bus bars through transfers and circuit breakers and these are

associated with different feeders through different equipment's.

Bus BARS: -

Bus bar is a term utilized for fundamental bar of conveyor conveying an electric

current to which numerous associations may be made. These are primarily a

helpful method for associating switches and other hardware's into different courses

of action.

Each switchyard have two bus bars. Most are made of aluminum and all the

approaching and active supplies are joined through the bus bars.

Important:-

Having three phase transmission, the phases are red, yellow and blue and if two of

three phases combine what happens? The answer is whole plant breakdown and

high spark will be produced because phase to phase and phase to neutral create

huge damage to plant.

CURRENT TRANSFORMERS: -

The main purpose of current transformer is to step down the current to a level that

the indicating and monitoring instruments can read. When rated current flows

through its primary winding, a current of nearly 1 amp will appear in its secondary

winding.The primary is so connected that the current being passes through it and

secondary winding is connected to an ammeter. The CT steps down the current to

the level of the ammeter. The ratio of current transformers is as follows

600/1,1200/1,2400/1 amperes.


LIGHTENING ARRESTORS: -

These are equipment’s designed to protect insulators of power lines and

electrical installations from lightening surges by diverting the surge to earth and

instantly restoring the circuit insulation to its normal strength with respect to earth.

The question is why high voltage has always fallen on Lightening Arrestors the

reason is it has zero ohms resistance, So, according to the Ohms Law if value of

resistance is low then high voltage and current will pass. So, that’s why the high

voltage sparks fell on it.. Lightening Arrestors having counters as well to count

how many times spark fall on it.

POTENTIAL TRANSFORMER:-

These are utilized to step do the voltage to a level that the potential curls of

showing and observing instruments can read. These are likewise used to bolster the

potential curls of transfers. The essential winding is joined with the voltage being

measured and the optional twisting to a voltmeter. The PT ventures down the

voltage to the level of the voltmeter.The potential transformers are joined in

parallel and present toward the end of the switch yard.

POWER TRANSFORMER: -

These are utilized to venture up,down the voltage starting with one A.C voltage

then onto the next AC voltage level at the same recurrence. Unit transformer takes

supply from helper transformer and exchanges it to switchyard transport bar.

WAVE TRAP: -

Wave trap is utilized to keep high recurrence signals from entering different zones.

NPCC is associated with all force stations through phone line which put their sign

on line and isolated from wave trap.

Demonstrating AND METERING INSTRUMENTS: -

Ammeters, voltmeters, Wattmeters, KWH meters, KVAR meters are introduced in

sub-station to watch over the streams,streaming in the circuit and the voltages and

the force loads.


ISOLATORS: -

One of the cardinal measures for guaranteeing the full well being in doing took a

shot at the hardware in electrical establishments is to separate dependably the unit

or the area on which the work is to be done from all other live parts of the

establishment. To make preparations for slip-ups, it is vital that contraption, which

makes a noticeable break in the circuit, for example, Isolators, ought to do this.

Isolators don't have circular segment control gadgets in this way can't be utilized to

intrude on streams at which the curve will be drawn over the contacts.


EARTHING SWITCHES:-

Earthing switch is used to discharge the voltage on deadlines to earth. An

auxiliary switch to provide interlock always accomplishes it.The earthing line

switches are helpful to ground all the inductions produced by other bus bars.

CIRCUIT BREAKERS: -

Circuit breakers are mechanical devices designed to close an open contact or

electrical circuit under normal or abnormal conditions. CB is equipped with a strip

coil directly attached to relay or other means to operate in abnormal conditions

such as over power, etc. In here, two types of CB are used. SF6 gas is used to

eliminate the spark that is produced by making a break of circuit breakers. Which

has 6 bar pressure and air is used to operate the breaker which has a pressure of

19bar. In block-3 switchyard portion breaker are hydraulically operated and air is

used for cooling. The hydraulic normal pressure is about 335 bar while SF6 normal

pressure is 7.6 bar while alarm and tripping pressure is about 7.2 and 7.1 bars

respectively.

Open, Close indication in Air blast Circuit breakers is as follows:

Green Color=Open

Red Color=Close

While in hydraulic Circuit Breaker:

1 represents Close

0 represents Open


Disc

The purpose for installation of the disc is to fulfill safe distance requirement

and also cover and isolate voltage as well. If one of three disc breaks the circuit

still complete and in running condition. And the safe distance achieved by

installing a number of discs between the metal bar and ground.

Safe distance for 220kV switch yard is =2. 4m.

Safe distance for 132kV switch yard is =1. 4m.

Breaker:

It is an on load device which is used for safety purpose. It makes the

different electric component separately in case of fault.

Trip Supervision:

To check the healthiness of breakers trip supervision is used which is in

parallel to the breaker and in case of failure of breaker it give command the other

one and operate related breakers.


Black Start

Crisis Function:

KAPCO is the exceptionally important force station of Pakistan on the grounds

that it has the office of self-begin. In the event of complete darkness, it can run its

self for this there is a Black has begun where the diesel generator produces power

empowers the excitation transport bars of GTS.

Bus Bar:

Dark begin transport bar is stimulated my DC batteries of 220V and help the diesel

generator to begin working

Diesel Generator:

Basically, it is not utilized, but rather as a part of instance of complete power

outage, it has exceptionally helped led to put force station without hesitation. It

gives 11 KV and stimulate the regular transport bar.


Neutral and Ground

Neutral:

A reference connection in a power distribution system.

Ground:

A connection to the earth or to a conductive object such as an equipment

chassis.There are two objectives to the intentional grounding of electrical

equipment:

• Keep potential voltage differentials between different parts of a system at a

minimum to reduce the shock hazard.

• Keep impedance of the ground path to a minimum. The lower the impedance, the

greater the current is in the event of a fault. The greater the current, the faster an

over current device will open

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