INTRODUCTION

In the realm of Space Exploration, where precision meets innovation, the

role of Electrical and Electronics Engineering is indispensable. The inplant training

program at ISRO Propulsion Complex (IPRC), Mahendragiri, unfolds as an

enlightening chapter for electrical and electronics students, offering a profound

journey into the technological forefront of propulsion systems. Nestled amidst the

serene landscapes of Mahendragiri, Tamil Nadu, ISRO Propulsion Complex

(IPRC) stands as a beacon of excellence in the field of propulsion technology. As

an integral part of the Indian Space Research Organisation (ISRO), IPRC

spearheads advancements in rocket propulsion, demanding the application of

cutting-edge electrical and electronics solutions. The primary objectives of the

inplant training program for electrical and electronics students at IPRC are to

provide an immersive experience in the integration of electronic systems with

propulsion technologies. The training aims to deepen the understanding of

electrical subsystems within rockets, emphasizing the critical role played by

electronics in ensuring the success of space missions.

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 CHAPTER 1

ISRO PROPULSION COMPLEX

1.1 IPRC

ISRO Propulsion Complex (IPRC) is one of the major research and

development centers under the Indian Space Research Organisation (ISRO). It is
dedicated to the testing, assembly, and integration of liquid propulsion stages for
launch vehicles and satellites. Located at Mahendragiri in Tamil Nadu, India, IPRC
plays a crucial role in advancing propulsion technologies for India's space
exploration endeavors.

IPRC was established in February 2002 with the primary focus on liquid
propulsion stages for launch vehicles and satellites. IPRC is a key center within the
ISRO family, contributing significantly to the development and testing of liquid
propulsion systems. The complex specializes in the testing of liquid propulsion
stages used in ISRO's launch vehicles. This includes testing engines and stages
under simulated conditions to ensure their reliability and performance.

IPRC is involved in the development and integration of liquid propulsion

systems, including cryogenic propulsion systems, which use liquid oxygen and
liquid hydrogen. The complex is equipped with state-of-the-art testing facilities,
including test stands and facilities for high-altitude tests, where engines and stages
undergo rigorous testing to simulate the conditions they will face during actual
launches.

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 IPRC is engaged in continuous research and development activities to
enhance and innovate liquid propulsion technologies. This includes exploring new
materials, technologies, and processes to improve efficiency and reliability.

The complex has made significant contributions to various ISRO space

missions, ensuring the successful deployment of satellites and launch vehicles. The
complex at Mahendragiri has expansive facilities for the assembly, integration, and
testing of liquid propulsion stages. The location is chosen for its strategic
advantage and environmental considerations. IPRC collaborates with various
national and international institutions, industries, and organizations to exchange
knowledge, expertise, and resources in the field of propulsion.

IPRC is also involved in educational initiatives, providing training and

internship opportunities for students and researchers in the field of aerospace
engineering and propulsion technologies.

1.2 What is Rocket?

A rocket is a vehicle or device that uses controlled explosions of propellant

material to generate thrust and propel itself through space or the Earth's
atmosphere. Rockets are commonly used for space exploration, satellite launches,
scientific research, and military applications.

1.3 ROCKET PRINCIPLE

The principle of rocket propulsion is based on Newton's third law of motion,

which states that for every action, there is an equal and opposite reaction. In the

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context of rocketry, this law is applied to the expulsion of propellant gases from the
rocket's engine to generate thrust and propel the rocket in the opposite direction.

1.4 LAUNCHING VEHICLES

Fig.1.4.1 GSLV MKIII

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Fig.1.4.2 GSLV MKII

5
Fig.1.4.3 PSLV

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 CHAPTER 2

VIKAS

ENGINE

ABOUT

In 1974, Societe Europeenne de Propulsion agreed to transfer Viking engine

technology in return for 100 man-years of engineering work from ISRO. The first
engine built from the acquired technology was tested successfully in 1985 ISRO
and named it Vikas.

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Fig.2 Vikas Engine

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2.1 TECHNICAL DETIALS

The Vikas (VIKram Ambalal Sarabhai) is a family of hypergolic liquid

fuelled rocket engines conceptualized and designed by the Liquid Propulsion
Systems Centre in the 1970s. The design was based on the licensed version of the
Viking engine with the chemical pressurisation system. The early production Vikas
engines used some imported French components which were later replaced by
domestically produced equivalents.

It is used in the Polar Satellite Launch Vehicle (PSLV), Geosynchronous

Satellite Launch Vehicle (GSLV) and LVM3 for space launch use.

Vikas Engine is used to power the second stage of PSLV, boosters and
second stage of GSLV Mark I and II and also the core stage of LVM3. The
propellant loading for Vikas engine in PSLV, GSLV Mark I and II is 40 tons,
while in LVM3 is 55 tons.

The Engine uses up about 40 metric tons of UDMH (Unsymmetrical

dimethylhydrazine) as fuel and Nitrogen tetroxide (N2O4) as oxidizer with a
maximum thrust of 725 kN. An upgraded version of the engine has a chamber
pressure of 58.5 bar as compared to 52.5 bar in the older version and produces a
thrust of 800 kN. The engine is capable of Gimballing.

The Vikas Engine uses Storable Propellants in a Pump-Fed Gas Generator

Cycle. Human rated Vikas Engine has higher structural margins for Sub-Systems,
improved assembly process and additional measurements for health monitoring.

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2.2 ASSEMBLY & INTEGRATION

2.2.1 VIKAS ENGINE PARTS

1. Gas Turbine
2. Turbo Pump
3. Main Engine Valve
4. Main Engine Tubes
5. Thrust Chamber
6. Injector
7. Nozzle

2.2.1.1 GAS TURBINE

In rocket engines, a gas generator is a subsystem that produces high-pressure

and high-temperature gases to drive a turbine, which, in turn, powers a turbopump.
The primary purpose of a gas generator is to provide the energy needed to operate
the turbopump, which pressurizes and delivers liquid propellants to the combustion
chamber for combustion.

2.2.1.2 TURBO PUMP

In Rocket engines, a turbo pump is a critical component that plays a key role
in delivering propellants to the combustion chamber at high pressure. Turbo pumps
are commonly used in liquid rocket engines, where liquid propellants are stored in
tanks and need to be pressurized and fed into the combustion chamber for
combustion.

1
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2.2.1.3 MAIN ENGINE VALVE

In a rocket engine, valves that control the flow of propellants (fuel and
oxidizer) to the combustion chamber. These valves play a critical role in regulating
the propellant flow, allowing for precise control over the engine's thrust and
performance. The main engine valves are essential components in the overall
propulsion system.

2.2.1.4 MAIN ENGINE TUBE

In a rocket engine, various tubes or pipelines that play crucial roles in the
functioning of the engine.

The specific design and function of engine tubes depend on the type of
rocket engine, the propellants used, and the intended mission. They are crucial for
maintaining the proper operation, cooling, and control of the rocket engine.

2.2.1.5 THRUST CHAMBER

The Thrust Chamber is a critical component in a rocket engine where the

combustion of propellants takes place, resulting in the generation of high-speed
exhaust gases that produce thrust. It is essentially the combustion chamber and
nozzle combined. The thrust chamber is responsible for converting the chemical
energy stored in the propellants into kinetic energy of the exhaust gases, propelling
the rocket forward.

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2.2.1.6 INJECTOR

In a rocket engine, the injector is a crucial component located at the entrance

of the combustion chamber. Its primary function is to spray and mix the liquid
propellants (oxidizer and fuel) in a way that facilitates efficient combustion. The
design and operation of the injector play a critical role in ensuring stable
combustion, optimal performance, and reliability of the rocket engine.

2.2.1.7 NOZZLE

The nozzle is a critical component in a rocket engine responsible for

accelerating and directing the high-speed exhaust gases produced during
combustion. The design of the nozzle is essential for maximizing the efficiency
and performance of the rocket propulsion system. There are different types of
nozzles, and their shape influences the expansion of exhaust gases, ultimately
determining the velocity and pressure at the exit of the nozzle.

2.3 SPECIFICATIONS

Thrust – 725KN in Sea Level and 799KN in Vaccum

Chamber Pressure – 6.2MPa(62 Bar)

Specific Impulse in Vaccum – 293sec(2.87 km/sec)

Specific Impule in Sea Level – 262sec(2.57 km/sec)

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 CHAPTER 3

CRYOGENIC ENGINE

Fig.3 Cryogenic Engine

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ABOUT

A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel and
oxidizer; that is, both its fuel and oxidizer are gases which have been liquefied and
are stored at very low temperatures. These highly efficient engines were first flown
on the US Atlas-Centaur and were one of the main factors of NASA's success in
reaching the Moon by the Saturn V rocket.

Rocket engines burning cryogenic propellants remain in use today on high

performance upper stages and boosters. Upper stages are numerous. Boosters
include ESA's Ariane 5, JAXA's H-II, ISRO's GSLV, LVM3, United States Delta
IV and Space Launch System. The United States, Russia, Japan, India, France and
China are the only countries that have operational cryogenic rocket engines.

3.1 CRYOGENIC PROPELLENTS

Rocket engines need high mass flow rates of both oxidizer and fuel to
generate useful thrust. Oxygen, the simplest and most common oxidizer, is in the
gas phase at standard temperature and pressure, as is hydrogen, the simplest fuel.
While it is possible to store propellants as pressurized gases, this would require
large, heavy tanks that would make achieving orbital spaceflight difficult if not
impossible. On the other hand, if the propellants are cooled sufficiently, they exist
in the liquid phase at higher density and lower pressure, simplifying tankage.
These cryogenic temperatures vary depending on the propellant, with liquid
oxygen existing below
−183 °C (−297.4 °F; 90.1 K) and liquid hydrogen below −253 °C (−423.4 °F; 20.1
K). Since one or more of the propellants is in the liquid phase, all cryogenic rocket
engines are by definition liquid-propellant rocket engines.
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 Various cryogenic fuel-oxidizer combinations have been tried, but the
combination of liquid hydrogen (LH2) fuel and the liquid oxygen (LOX) oxidizer
is one of the most widely used. Both components are easily and cheaply available,
and when burned have one of the highest enthalpy releases in combustion,
producing a specific impulse of up to 450 s at an effective exhaust velocity of 4.4
kilo metres per second (2.7 mi/s).

3.2 COMPONENTS

1. Combustion Chamber
2. Pyrotechnic Initiator
3. Fuel Injector
4. Fuel and Oxidizer Turbopumps
5. Cryo Valves
6. Regulators
7. Nozzle

3.3 COMBUSTION CYCLE

In terms of feeding propellants to the combustion chamber, cryogenic rocket

engines are almost exclusively pump-fed. Pump-fed engines work in a gas-
generator cycle, a staged-combustion cycle, or an expander cycle. Gas-generator
engines tend to be used on booster engines due to their lower efficiency, staged-
combustion engines can fill both roles at the cost of greater complexity, and
expander engines are exclusively used on upper stages due to their low thrust.

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 Fig.3.3 Combustion Cycle

3.4 SPECIFICATIONS

Fuel - Liquid Hydrogen (LH2)

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Fuel Temperature - -183°C

Oxidizer - Liquid Oxygen

(LOX) Oxidizer Temperature - -

253°C Specific Impulse – 450sec

Chamber Pressure – 40Bar

Thrust – 50KN

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 CHAPTER 4

SEMI CRYOGENIC ENGINE

Fig.4 Semi cryogenic Engine

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ABOUT

The SCE-200 (Semi-Cryogenic Engine-200) is a 2 MN thrust class liquid

rocket engine, being developed to power ISRO's existing LVM3 and upcoming
heavy and super heavy-lift launch vehicles. It is being developed by Liquid
Propulsion Systems Centre (LPSC) of ISRO.

Burning liquid oxygen (LOX) and RP-1 Iserosene (Kerosene) in an oxidizer-

rich staged combustion cycle, the engine will boost payload capacity of LVM3
replacing current L110 stage powered by two Vikas engines. It is also expected to
power ISRO's upcoming Next Generation Launch Vehicle (NGLV) rockets
(previously planned as ULV) as well as ISRO's future reusable rockets based on
RLV technology demonstrations.

The engine in September 2019 reportedly had become ready to begin testing in
Ukraine and enter service no earlier than 2022. The use of engine of India's first
human spaceflight, hence was ruled out by ISRO. By November 2022, SCE-200
had neared completion of its qualification tests. Stage and development had been
complete and a facility to test it at ISRO Propulsion Complex Mahendergiri was
getting ready for ground tests.

4.1 DEVELOPMENT & TESTING

On 10 May 2023, the first integrated test on an intermediate configuration of

the 2000 kN Semi cryogenic Engine was conducted at Semicryogenic Integrated
Engine & Stage Test facility in IPRC, Mahendragiri. During the test lasting 15
hours, complex chill-down operations were performed to meet necessary
conditions for engine start.

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 On 1 July 2023, the first hot test on an intermediate configuration of the
Semi- cryogenic Engine, known as Power Head Test Article (PHTA) was
conducted at SIET facility of IPRC, Mahendragiri. The test proceeded nominally
till 1.9 seconds validating the ignition and subsequent performance of PHTA. At
2.0 seconds, an unexpected spike in the turbine pressure and subsequent loss of
turbine-speed was observed. The test was terminated mid-way as a precaution and
further analysis is in progress. The intended duration of test was 4.5 seconds to
validate the performance of the gas generator, turbo pumps, pre-burner and control
components with focus on the ignition and hot-gas generation within the pre-
burner chamber.

4.2 SPECIFICATIONS

Fuel – Iserosene (Kerosene)

Oxidizer – Liquid Oxygen (LOX)

Specific Impulse in Vacuum – 335sec(3.29km/sec)

Specific Impulse in Sea Level – 299sec(2.93km/sec)

Chamber Pressure – 18MPa

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 CHAPTER 5

STAGES

ABOUT

Rockets typically consist of multiple stages, each designed to function

during different phases of the launch. The use of multiple stages allows the rocket
to shed mass as it ascends, making it more fuel-efficient.

5.1 EARTH STORABLE STAGE

Earth-storable rocket stages are designed to use propellants that remain in a

stable state at ambient temperatures on Earth. These stages are advantageous for
their ability to be stored for extended periods without the need for special handling
or cooling equipment. Typically, hypergolic propellants are used in these stages, as
they ignite spontaneously upon contact with each other. This eliminates the need
for an ignition system, making these rockets reliable and suitable for a wide range
of missions.

5.2 L110 STAGE

The L110 is a liquid core stage used in the GSLV Mk III (Geosynchronous
Satellite Launch Vehicle Mark III), which is an expendable launch vehicle
developed by the Indian Space Research Organisation (ISRO). The GSLV Mk III
is
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designed to carry heavier payloads into geostationary transfer orbit (GTO) and low
Earth orbit (LEO). The L110 stage serves as the second stage of the GSLV Mk III.

The L110 stage is powered by liquid propellants. It uses unsymmetrical

dimethyl hydrazine (UDMH) as fuel and nitrogen tetroxide (N2O4) as an oxidizer.
These hypergolic propellants ignite spontaneously upon contact, eliminating the
need for an ignition system.

Fig.5.2 L110 Stage

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5.2.1 SPECIFICATIONS

Height - 43.43 m (142.5 ft)

Diameter - 4 m (13ft)

Mass - 640,000 kg (1,410,000 Bar)

Volume – 50,000 L

Firing Duration – 200 sec

5.3 CRYO UPPER STAGE (CUS)

A cryogenic upper stage in a rocket refers to the use of cryogenic propellants

in the uppermost stage of the launch vehicle. Cryogenic propellants are those that
exist in a liquid state at extremely low temperatures. The two most common
cryogenic propellants used in rocketry are liquid oxygen (LOX) as the oxidizer and
liquid hydrogen (LH2) as the fuel. It is used in GSLV MK II. & MKIII.

The payload fairing is a protective shell that surrounds the payload during
the rocket's ascent through the Earth's atmosphere. It shields the payload from
aerodynamic forces and environmental conditions. Once the rocket reaches space,
and atmospheric forces are no longer a concern, the payload fairing is jettisoned to
expose the payload to space

.The material are used Stainless Steel, Aluminium Alloy(Al 2219), Titanium
and Polymaid. It is made up on no Bold and Joints. They are fully Welded Material
are used

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 .

Fig.5.3 Cryo Upper Stage

5.3.1 SPECIFICATIONS

Payload – 20 tons

Fuel – Liquid Hydrogen(LH2) and Liquid Oxygen(LOX)

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5.4 C25 STAGE

The C25 stage is a cryogenic upper stage developed by the Indian Space
Research Organisation (ISRO) for its Geosynchronous Satellite Launch Vehicle
Mark III (GSLV Mk III). It is the most powerful upper stage developed by ISRO
and uses Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) propellant
combination
. The stage carries 27.8 tons of propellants loaded in two independent tanks . The
C25 stage comprises a cryogenic engine and fuel tanks that hold tons of frozen
fuel, along with its related systems.

Engineering a cryogenic stage has unique design challenges, as liquid

Hydrogen is stored at -253 degree centigrade and liquid Oxygen at -195 degree
centigrade.

5.4.1 SPECIFICATIONS

Tank Material – Aluminium

Pipe Line Material – Stainless Steel

Tank Capacity – 21 m3

Fuel Mixed Ratio – 5:1

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Fig.5.4 C25 Stage

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 CHAPTER 6

TEST STAND FACILITY

ABOUT

Rocket engine test stands are crucial facilities used for testing and validating
rocket engines before they are integrated into a complete launch vehicle. These test
stands provide a controlled environment for engineers to assess the performance,
reliability, and safety of rocket engines

6.1 HIGH ALTITUDE TEST

High altitude tests for rocket engines are conducted to simulate the
conditions that a rocket will experience during its flight through the Earth's
atmosphere. These tests are essential for evaluating the performance, reliability,
and operational characteristics of rocket engines under low-pressure and low-
density conditions typically encountered at high altitudes.

6.2 PRINCIPLE TEST STAND

A rocket engine test stand is a critical facility for testing and evaluating
rocket engines before they are integrated into a complete launch vehicle. The test
stand serves as a controlled environment where engineers can assess the engine's
performance, validate design parameters, and identify any potential issues.

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Fig.6.2 Principle Test Stand

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6.3 AUXILIARY TEST STAND

An Auxiliary Test Stand in the context of rocket engines typically refers to a

secondary or additional test stand that supports specific aspects of rocket engine
development, testing, or research. The auxiliary test stand is designed to
complement the primary test stand and may focus on certain subsystems,
components, or specialized testing requirements.

6.4 REMOTE CONTROL TEST

A Remote Control (RC) test stand for rocket engines is a facility designed to
enable remote operation and monitoring of rocket engine tests. This type of test
stand enhances safety by allowing operators to control the testing process from a
safe distance.

6.5 LIQUID THRUST TEST FACILITES

LTTF for testing liquid rocket engines involve complex setups to simulate
the conditions that engines will experience during actual launches. These facilities
are crucial for validating the performance, reliability, and safety of liquid
propulsion systems.

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6.6 SEMI CRYOGENIC INTEGRATED ENGINE TEST

The Semi Cryogenic Integrated Engine Test Complex (SIET) is a facility

designed for testing the SCE-200 Semi-Cryogenic kerolox (iserosene) engine. This
engine is a crucial component of the LVM3 launch vehicle future upgrade,
replacing the pair of Vikas engines on its first stage. This is newly established test
facility at ISRO Propulsion Complex (IPRC) is capable of testing semi-cryogenic
engines up to 2600 kN thrust and will support the subsequent testing and
qualification of the fully integrated Semi Cryogenic engine and stage. The
inaugural integrated test of the semi-cryogenic engine took place at the IPRC.

6.7 CRYO MAIN ENGINE & STAGE TEST

Cryogenic rocket engines use propellants that are stored and handled at
extremely low temperatures. Typically, liquid oxygen (LOX) and liquid hydrogen
(LH2) are common cryogenic propellants. Testing cryogenic rocket engines
involves specialized facilities designed to handle these cryogenic conditions.

6.8 TRUST CHAMBER TEST

Testing the thrust chamber in a rocket engine is a crucial step in the

development and validation of a rocket propulsion system. The thrust chamber is a
critical component responsible for generating thrust by expelling high-speed
exhaust gases produced from the combustion of propellants. Conducting thorough
and rigorous tests on the thrust chamber helps ensure its reliability, performance,
and safety.

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 CHAPTER 7

COATING & WELDING

7.1 COATING

Coatings play a critical role in the aerospace sector, where components and
structures are exposed to extreme conditions, including high temperatures,
corrosive environments, and aerodynamic forces. Aerospace coatings serve various
purposes, ranging from protection against corrosion to enhancing the overall
performance and durability of aircraft.

In IPRC there are two types of Coating used. They are

1. Thermal Barrier Coating.

2. Wear Resistance Coating.

7.1.1 THERMAL BARRIER COATING

Thermal barrier coatings (TBCs) are advanced materials applied to the

surfaces of components exposed to high temperatures, such as gas turbine engine
parts, industrial furnaces, and aerospace components. These coatings are designed
to provide thermal insulation, protecting underlying materials from the extreme
temperatures encountered in such environments. The Zirconium oxide Powder are
used as the Coating material in (TBC).

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In IPRC mainly used Two types of Thermal Barrier Coating. They are

1. Flame Spray Coating.

2. Plasma Spray Coating.

7.1.1.1 FLAME SPRAY COATING

Flame spray, specifically oxy-fuel flame spray, is a thermal spray coating

process where a coating material is melted and propelled onto a substrate surface
using a high-temperature flame generated by the combustion of oxygen and a fuel
gas. This method is commonly used for applying coatings to enhance properties
such as corrosion resistance, wear resistance, and thermal insulation

7.1.1.2 PLASMA SPRAY COATING

Plasma spraying is a widely used technique for applying Thermal Barrier

Coatings (TBCs), especially in high-temperature applications such as the aerospace
and gas turbine industries. TBCs are designed to provide thermal insulation and
protect components from extreme heat.

7.1.2 WEAR RESISTANCE COATING

While Thermal Barrier Coatings (TBCs) are primarily designed to provide

thermal insulation and protect components from high temperatures, wear-resistant
coatings can be applied in conjunction with TBCs to enhance the wear resistance
of components in certain applications. This combination is particularly relevant in
situations where components are exposed to both high temperatures and wear.
Chromium(III) oxide Powder are used to a coating material.
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7.2 WELDING

Welding is a fabrication process used to join materials, usually metals or

thermoplastics, by causing coalescence. This is often done by melting the
workpieces and adding a filler material to form a pool of molten material that cools
to become a strong joint.

There are mainly Three types of Welding used in IPRC. They are

1. Electron Beam Welding.

2. Orbital Welding.
3. TIG Welding.

7.2.1 Electron Beam Welding (EBW)

Electron Beam Welding (EBW) is a high-energy welding process that

utilizes a focused beam of electrons to join metals with precision and efficiency.
This process is commonly used in industries where fine and deep welds are
required, such as aerospace, automotive, and electronics manufacturing.

It is unconventional welding and also one of the permanent joint welding. Its
requires high voltage 60KW and its produce above 1500°C.

7.2.2 ORBITAL WELDING

Orbital welding is an automated welding process used for joining pipes and
tubes with a high level of precision. This process involves rotating the welding
electrode around the workpiece in a circular or orbital motion while simultaneously
moving the electrode along the joint. Orbital welding is commonly used in
32
industries

33
where high-quality, consistent and repeatable welds. In job is symmetrical this type
of welding preferred.

7.2.3 TIG WELDING

Tungsten Inert Gas (TIG) welding, also known as Gas Tungsten Arc
Welding (GTAW), is a precision welding process that uses a non-consumable
tungsten electrode to create an arc. TIG welding is known for its versatility,
producing high- quality welds across various materials joining critical components
and structures. The aerospace industry demands high-quality, precise, and reliable
welding processes, and TIG welding is well-suited to meet these requirements.

TIG welding is often employed in the fabrication of critical components in

aerospace, such as aircraft frames, fuselage sections, engine components, and
structural elements. The precise control and high-quality welds produced by TIG
welding are crucial for ensuring the structural integrity and reliability of these
components.

TIG welding is used for repair and maintenance of aerospace components.

Whether it's repairing cracks in structural elements or addressing minor damages,
TIG welding allows for precise and controlled repairs.

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 CHAPTER 8

ELECTRICAL CONSTRUCTION AND MAINTANANCE

8.1 SUBSTATION

A substation is a key component in the electrical power system that plays a

crucial role in transmitting and distributing electricity. It serves as an intermediate
point between the high-voltage transmission system and the low-voltage
distribution system, facilitating the transformation of voltage levels and the
distribution of electrical power to consumers. Substations are strategically located
throughout the power grid to manage and control the flow of electricity.

In IPRC Main Substation 110KV/33KV, 33KV/11KV HT to LT.

8.1.1 FUNCTION OF (110KV/33KV) & (33KV/11KV)

SUBSTATION

A substation with a voltage level of (110 kV/33 kV) and (33KV/11KV)

performs several essential functions in an electrical power system.

The specific functions of a substation at this voltage level include:

1. Step-Down - The substation steps down the incoming high-voltage electricity

(110 kV) and (33KV) to a lower voltage level (33 kV) and (11KV) for further
distribution to downstream substations or directly to industrial and commercial
consumers.

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2. Switching Devices - The substation includes various switching devices such as
circuit breakers, disconnect switches, and isolators. These devices are used to
control the flow of electricity, allowing for the isolation of faulty sections or
equipment during maintenance and repairs.
3. Circuit Protection - The substation provides protection against electrical faults,
such as short circuits or overloads, using protective relays and circuit breakers.
4. The substation serves as an intermediate point between the higher-voltage
transmission network and lower-voltage distribution networks. It distributes
electricity to downstream substations, industrial areas, and commercial zones.
5. The substation may include voltage regulation equipment to maintain a stable
voltage level within acceptable limits. This ensures that the electrical power
supplied to consumers meets quality standards.
6. Control Systems - Substations are equipped with control systems that allow
operators to monitor and control various components remotely.
7. Monitoring - Continuous monitoring of parameters such as voltage, current, and
temperature helps ensure the reliability and efficiency of the substation.
8. Power Transformers - Step-down transformers are employed to reduce the
voltage from 110 kV to 33 kV. These transformers are critical components for
voltage transformation and play a key role in the substation's operation.
9. Grounding Systems - Proper grounding is implemented to provide safety for
personnel and equipment by ensuring that fault currents are safely dissipated
into the ground.
10.Safety Measures - Substations adhere to safety standards and incorporate
features such as fencing, warning signs, and safety interlocks to prevent
unauthorized access and enhance safety.
11.Substations may have communication systems for real-time monitoring,
control, and data exchange with the central control center.
36
 12.Regular maintenance and inspections are conducted to ensure the proper
functioning of equipment and identify potential issues before they lead to failures.
13.Environmental aspects such as landscaping, noise reduction measures, and
containment of oil-filled equipment are considered to minimize the impact on the
surroundings.

8.2 TRANSFORMER

A transformer is an electrical device that transfers electrical energy between

two or more circuits through electromagnetic induction. It does this by changing
the voltage level of an alternating current (AC) while keeping the frequency the
same. Transformers are fundamental components in electrical power systems, used
for various purposes such as stepping up or stepping down voltage levels, isolation,
and impedance matching.

8.3 VOLTAGE TRANSFORMER

A voltage transformer, also known as a potential transformer (PT) or a

voltage sensor, is a device used in electrical power systems to transform high
voltage levels into lower, standardized values for measurement and protection
purposes. The primary function of a voltage transformer is to provide a scaled-
down replica of the voltage across its primary winding to its secondary winding,
which is connected to instruments, relays, or control devices. These devices
typically operate at lower voltage levels, making them more suitable for
measurement and control.

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8.4 CURRENT TRANSFORMER

A current transformer (CT) is a type of instrument transformer used in

electrical power systems to measure and monitor alternating current (AC) flowing
in a circuit. The primary function of a current transformer is to transform the high
primary current flowing through its primary winding into a standardized,
proportionally reduced current suitable for measuring instruments and protective
devices. Current transformers play a crucial role in ensuring accurate current
measurement and providing inputs to protection relays and meters.

8.5 CABLES

A cable is a structure consisting of one or more conductors that are insulated

and often bundled together. Cables are used for transmitting electrical power or
signals from one point to another. They come in various types, sizes, and designs,
serving different purposes in electrical and communication systems. The
conductors within a cable can be made of copper, aluminum, or other materials
with good electrical conductivity.

8.6 BUSBAR

A busbar is a metallic strip or bar that serves as a common electrical

conductor for the distribution of electric power within an electrical substation,
switchyard, or industrial facility. Busbars are typically made of copper or
aluminum due to their excellent electrical conductivity. They play a critical role in
efficiently distributing electric power from one point to multiple points in a power
system.
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8.7 BUSCOUPLER

A bus coupler, also known as a bus tie, is a device used in electrical power
systems to connect two or more electrical buses together. The primary function of
a bus coupler is to enable the transfer of electrical power between different sections
of a power distribution system, ensuring redundancy, flexibility, and reliability.

8.8 SURGE ARRESTER

A surge arrester, also known as a surge suppressor or transient voltage

suppressor, is a protective device used in electrical and electronic systems to limit
transient overvoltage conditions, such as voltage spikes and surges. Surge arresters
are designed to divert excessive voltage away from sensitive equipment,
preventing damage caused by transient events like lightning strikes, switching
operations, or other electrical disturbances.

8.9 EARTHING

Earthing, also known as grounding, is a safety and electrical engineering

practice that involves connecting electrical systems, equipment, and structures to
the Earth or a reference ground point. The primary purpose of earthing is to ensure
safety by providing a low-resistance path for fault currents to flow into the ground,
minimizing the risk of electric shock, fires, and equipment damage.

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8.10 DIESEL GENERATOR

A Diesel Generator is a type of generator set that uses a diesel

engine to generate electrical energy. It is a common and reliable source
of backup power, especially in situations where a continuous and stable
power supply is crucial. Diesel generators are widely used in various
applications, including residential, commercial, industrial, and emergency
power systems.

Capacity:

Rating: 320 kilovolt-amperes (kVA) indicates the apparent power capacity of the
generator.

Fuel Type:

Fuel: Diesel generators are powered by diesel fuel, which is commonly used for
its energy density and stability.

Engine Details:

Type: The generator would be equipped with a diesel engine.

Power Output: The engine's power output would be designed to meet the generator's
rated capacity.

Cooling System: Diesel engines typically have a cooling system to maintain optimal
operating temperatures.

Alternator (Generator Head):

Type: Brushless, synchronous alternator.

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0
 Voltage Output: The generator would produce electrical output at a specific
voltage, commonly 400/230V in three-phase systems.

Control Panel:

Features: The control panel includes instruments and controls for monitoring
and managing the generator's operation. This may include voltage meters,
frequency meters, control switches, and alarms.

Fuel System:

Tank Capacity: Diesel generators often have an integrated fuel tank, and the
capacity would depend on the specific design. Alternatively, the generator might
be connected to an external fuel source.

Run Time:

Continuous Operation: Generators are often designed for continuous operation or

have a specified duty cycle.

Enclosure:

Type: The generator may be housed in an enclosure to protect it from

environmental conditions and reduce noise levels.

Voltage Regulation:

AVR (Automatic Voltage Regulator): The generator would typically be equipped

with an AVR to maintain a stable output voltage.

Protection and Safety Features:

Generators come with safety features such as overload protection, low oil
pressure shutdown, high-temperature shutdown, and other safety mechanisms.

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 CHAPTER 9

INTEGRATED ELECTRICAL SERVICES

ABOUT

Electrical Integrated Service generally is a comprehensive and coordinated

set of services related to electrical systems and infrastructure within a facility or
organization. It involves the integration of various electrical components, systems,
and services to ensure seamless operation, efficiency, and reliability of the
electrical infrastructure. The term can cover a wide range of activities and services.

9.1 BREAKERS

Circuit breakers are electrical devices designed to protect electrical circuits

and equipment from overcurrents and short circuits. They play a crucial role in
electrical systems by interrupting the flow of current when abnormal conditions are
detected, preventing damage to the circuit and connected devices. Circuit breakers
are commonly used in residential, commercial, and industrial applications.

9.2 AIR CIRCUIT BREAKER

An Air Circuit Breaker (ACB) is a type of circuit breaker that uses air as the
medium for arc extinction. It is a common and widely used circuit breaker in low-
voltage electrical distribution systems, providing protection against overloads,
short circuits, and ground faults. Air circuit breakers are often employed in
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industrial and

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commercial applications where higher current ratings and robust performance are
required.

9.3 VACUUM CIRCUIT BREAKER

A Vacuum Circuit Breaker (VCB) is a type of circuit breaker that uses

vacuum as the interrupting medium for extinguishing the electric arc during circuit
interruption. Vacuum circuit breakers are commonly employed in medium-voltage
(MV) and high-voltage (HV) applications, offering several advantages over other
types of circuit breakers.

9.4 OIL CIRCUIT BREAKER

An Oil Circuit Breaker (OCB) is a type of circuit breaker that uses oil as
both an insulating medium and an arc extinguishing medium. Oil circuit breakers
were commonly used in high-voltage electrical systems, particularly in power
distribution substations and industrial applications. However, their usage has
significantly decreased in recent years due to environmental concerns associated
with the use of oil and the development of alternative technologies.

9.5 MINIATURE CIRCUIT BREAKER

A Miniature Circuit Breaker (MCB) is a type of circuit breaker that is

designed to protect electrical circuits from over currents and short circuits. MCBs
are widely used in residential, commercial, and industrial electrical distribution

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boards due to their compact size, ease of installation, and efficient protection
capabilities.

9.6 MOLDED CASE CIRCUIT BREAKER

A Molded Case Circuit Breaker (MCCB) is a type of circuit breaker that is

widely used for electrical distribution and protection in low-voltage applications.
MCCBs are designed to provide reliable over current protection and are commonly
used in residential, commercial, and industrial settings. The term "molded case"
refers to the plastic or insulating material housing that encloses the internal
components of the circuit breaker.

9.7 EARTH LEAKAGE CIRCUIT BREAKER

An Earth Leakage Circuit Breaker (ELCB) is a type of circuit breaker that is

specifically designed to protect against electric shock and electrical fires caused by
earth faults or leakage currents. It is also commonly known as a Ground Fault
Circuit Interrupter (GFCI) in some regions. ELCBs are widely used in residential,
commercial, and industrial electrical installations.

9.8 RELAY

A relay is an electrically operated switch that uses an electromagnetic coil to

control the opening and closing of one or multiple sets of contacts. Relays play a
crucial role in various electrical and electronic systems, providing a means to
control
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high-power circuits with low-power signals. They are commonly used for
automation, control, and protection in a wide range of applications.

9.9 MOTOR PROTECTION RELAY

A Motor Protection Relay is a specialized type of protective relay designed

to monitor and protect electric motors from abnormal operating conditions and
faults. Motors are critical components in various industrial processes, and motor
protection relays play a crucial role in ensuring the reliability and safety of motor-
driven systems. These relays are commonly used in industries such as
manufacturing, petrochemical, utilities.

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 CONCLUSION

The inplant training at ISRO Propulsion Complex has been a transformative

journey for us as Electrical and Electronics Engineering. Our exposure to the
intricacies of propulsion systems, including Vikas, Cryogenic, and Semi Cryogenic
engines, as well as rocket stages, has significantly enhanced our understanding of
the vital role played by electrical and electronic components in space exploration.
Hands-on experiences in testing facilities, electrical construction, and maintenance
have provided practical insights, bridging the gap between theory and application.
The training has not only strengthened our technical skills but also instilled a sense
of precision and attention to detail crucial in the aerospace industry. The integrated
electrical services at ISRO have showcased the synergy between various electrical
components in ensuring the success of space missions. This inplant training has
equipped us with a holistic perspective, preparing us for the challenges of a
dynamic and high-stakes industry. As we conclude this enriching experience, we
express our gratitude to the ISRO Propulsion Complex team for their mentorship
and support. This training has been a cornerstone in our academic journey, and we
are eager to apply the knowledge gained in our future endeavors.

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