1. DAY 1
• Overview About ONGC
• Visit to different department buildings of ONGC
Maharatna ONGC is the largest crude oil and natural gas Company in India, contributing around
70 per cent to Indian domestic production. Crude oil is the raw material used by downstream
companies like IOC, BPCL, and HPCL to produce petroleum products like Petrol, Diesel, Kerosene,
Naphtha, and Cooking Gas-LPG.
This largest natural gas company ranks 11th among global energy majors (Platts). It is the only
public sector Indian company to feature in Fortune’s ‘Most Admired Energy Companies’ list.
ONGC ranks 18th in ‘Oil and Gas operations’ and 183rd overall in Forbes Global 2000. Acclaimed
for its Corporate Governance practices, Transparency International has ranked ONGC 26th
among the biggest publicly traded global giants. It is most valued and largest E&P Company in
the world, and one of the highest profit-making and dividend-paying enterprise.
ONGC has a unique distinction of being a company with in-house service capabilities in all areas
of Exploration and Production of oil & gas and related oil-field services. Winner of the Best
Employer award, this public-sector enterprise has a dedicated team of over 33,500 professionals
who toil round the clock in challenging locations.
ONGC Videsh is a wholly owned subsidiary of Oil and Natural Gas Corporation Limited (ONGC),
the National Oil Company of India, and is India’s largest international oil and gas Company. ONGC
Videsh has participation in 41 projects in 20 countries namely Azerbaijan, Bangladesh, Brazil,
Colombia, Iraq, Israel, Iran, Kazakhstan, Libya, Mozambique, Myanmar, Namibia, Russia, South
Sudan, Sudan, Syria, United Arab Emirates, Venezuela, Vietnam and New Zealand. ONGC Videsh
maintains a balanced portfolio of 15 producing, 4 discovered/under development, 18 exploratory
and 4 pipeline projects. The Company currently operates/ jointly operates 21 projects. ONGC
Videsh had total oil and gas reserves (2P) of about 711 MMTOE as on April 1, 2018.
ONGC Videsh was incorporated as Hydrocarbons India Pvt. Ltd. on 5 March 1965 to carry out
exploration and development of the Rostam and Raksh oil fields in Iran and undertaking a service
contract in Iraq. The company was rechristened as ONGC Videsh Limited on 15 June 1989 with
the prime objective of marketing the expertise of ONGC abroad. The nineties saw the Company
engaged in limited exploration activities in Egypt, Yemen, Tunisia and Vietnam.
In its new avatar as ONGC Videsh, the company from mid-nineties re-oriented its focus on
acquiring quality overseas oil and gas assets. ONGC Videsh, which had one asset in the year 2000,
gradually succeeded in competing with the best in international arena and could conclude many
large transactions across the world in subsequent years.
2. During the year ended March 31, 2018, following awards and recognitions were conferred upon
• The President of India conferred the prestigious SCOPE award for Excellence and Outstanding
Contribution to the Public-Sector Management – Institutional Category II (Miniratna-I & II
PSEs) for 2014-15 on April 11, 2017.
• Golden Peacock Award for Risk Management 2017 instituted by the Institute of Directors
(IOD) during Global Convention on Corporate Ethics & Risk Management.
• The ICICI Lombard & CNBC-TV18 India Risk Management Award in the category of “Best Risk
Management Framework & Systems – Risk Technology”.
• Strategic Performance Award in Miniratna-I category at the 5th edition of Governance Now
ONGC has taken structured initiatives towards Corporate Governance and its practices which
evolve around multi-layered checks and balances to ensure transparency. Apart from the
mandatory measures required to be implemented as a part of Corporate Governance, ONGC has
gone the extra mile in this regard and has implemented the Whistle Blower Policy, Annual Report
on working of the Audit & Ethics Committee, MCA Voluntary Guidelines on Corporate
Governance, Enterprise-wide Risk Management (ERM) framework.
Health, Safety & Environment
ONGC has implemented globally recognized QHSE management systems conforming to
requirements of ISO 9001, OHSAS 18001 and ISO 14001 at ONGC facilities and certified by
reputed certification agencies at all its operational units. Corporate guidelines on incident
reporting, investigation and monitoring of recommendations has been developed and
implemented for maintaining uniformity throughout the organization in line with international
Corporate Disaster Management Plan and guidelines have been developed for uniform disaster
management across ONGC. ONGC has also developed Occupational Health physical fitness
criteria for employees deployed for offshore operations. Occupational Health module has now
been populated on SAP system.
This largest energy company has vast pool of skilled and talented professionals – the most asset
for the company. ONGCians dedicate themselves for the excellent performance of the company.
ONGC extends several welfare benefits to the employees and their families by way of
comprehensive medical care, education, housing and social security.
To be global leader in integrated energy business through sustainable growth, knowledge
excellence and exemplary governance practices.
➢ World Class
• Dedicated to excellence by leveraging competitive advantages in R&D and technology
with involved people.
• Imbibe high standards of business ethics and organizational values.
• Abiding commitment to safety, health and environment to enrich quality of community
• Foster a culture of trust, openness and mutual concern to make working a stimulating
and challenging experience for our people.
• Strive for customer delight through quality products and services
➢ Integrated in Energy Business
• Focus on domestic and international oil and gas exploration and production business
• Provide value linkages in other sectors of energy business.
• Create growth opportunities and maximize shareholder value.
➢ Dominant Indian Leadership
• Retain dominant position in Indian petroleum sector and enhance India's energy
➢ Carbon Neutrality
• ONGC will continually strive to reduce CO2 emissions across its activity chain with
the objective of achieving carbon neutrality
➢ TECHNOLOGY USED IN ONGC
ONGC is one of the largest E&P Company in India with in-house service capabilities in all the
activity areas of exploration and production of oil & gas and related oil-field services. The state-
of-the-art technologies inducted and absorbed over the years such as depth domain processing,
stratigraphic inversion, advanced volume-based interpretation tools, stochastic lithifies modeling
using neural network, spectral decomposition, geo-statistical modeling, etc.
ONGC has set benchmarks for industry to follow. ONGC has setup EPINET, through which a live
E&P information network and a virtual database has been developed for Basin & Petroleum
System Modeling of various basins. Through SCADA all production and drilling executives at
different levels utilize and reap benefits of online SCADA data for enhanced operational efficiency
4. ➢ 3-D virtual reality centers
ONGC has set up four 3-D virtual reality centers known as 'Third Eye' for real time dissemination
and information of onshore and offshore applications. These centers are used for exploration and
production activities including real-time surveillance of producing oil and gas fields thus helping
ONGC network all its centers together by parallel computing technologies for all the major
➢ SAP implementation started by ONGC’s management
Thinking ahead of times, in 2002, ONGC’s management started the SAP implementation, which
turned out to be the largest India has ever seen. ONGC is now moving towards a paperless office
through adoption of latest pioneering technologies.
➢ Project ICE
ONGC has also implemented an enterprise-wide ERP implementation by the name of Project ICE.
It comprised of 23 SAP modules in more than 500 physical locations across the length and breadth
of the country, starting from mobile Survey units at Jwalamukhi of Himachal Pradesh to Deep Sea
vessels at Bay of Bengal, from Production installations at far flung areas of Assam to Drilling rigs
in the desert of Rajasthan.
➢ Sustainable Development is the overarching working template in ONGC which finds
expression in its commitment to continually enhance the triple bottom line benchmarks
of economic, environmental and social performance.
➢ ONGC realized that focused carbon management efforts were an ideal route to cover the
elements of their business specific sustainable development issues across the
environmental dimension. A critical area of environmental sustainability is mitigation of
global greenhouse gas from operations.
➢ ONGC has six registered CDM projects (a unique feat amongst CPSEs) with a total saving
of 2,09,643 tons of CO2 per year for 10 years. Six more CDM projects are under
registration which will significantly add to the portfolio of ONGC's carbon credits.
➢ To fulfill the organizational objective of corporate sustainability ONGC is progressively
working towards reducing their carbon footprint, by reducing both direct and indirect
energy consumption. ONGC plans to make a comprehensive, organization wide GHG
inventory that covers both direct and indirect energy over the next two to three years.
This would provide the overall carbon footprint of the organization and help identify
mitigation opportunities. A pilot exercise to assess GHG footprint of ONGC's
representative operating units has already been completed. This pilot is now being scaled
up into a pan ONGC GHG accounting exercise to assess the Company's organisational
carbon footprint and importantly to undertake a rigorous study for identification of all
feasible GHG mitigation opportunities. The pan ONGC carbon foot printing exercise is
likely to be completed in 2013 and provide a number of viable mitigation projects at hand
to work upon.
5. ONGC ENERGY CENTER
Uranium Exploration and In-Situ Leaching for Recovery
➢ Uranium can be extracted by open surface mining, commonly in practice in India, or by In-
Situ Leaching (ISL) from sub-surface, as practiced in some countries like USA, Australia, and
Kazakhstan etc. At present, ISL process for Uranium extraction has not been fully developed
and demonstrated as yet in the country.
➢ In view of the advantages of the ISL method for Uranium recovery from sub-surface, OEC has
taken up research for exploration of sub-surface Uranium which could be amenable for
extraction through in-situ leaching (ISL). The initial analysis of the well log data of oil wells
drilled by ONGC is being done by OEC to identify possible areas suitable for detailed analysis,
modeling and experimental validation. This is followed by building geological models, using
geo-scientific methods for validation of model/prospects by drilling, coring and electro-
logging; geo-chemical and petro-physical analysis of cores, in order to assess the resource
potential and its suitability for ISL process, at any specific region. These experiments are being
used to develop a model to carry out In-Situ Leaching process development and its
experimental validation. OEC has set up laboratory facilities at Ahmedabad for initial testing,
characterization and modeling for both exploration work and ISL process development. The
OEC laboratory for Uranium is located in a separate building in ONGC Complex, Ahmedabad.
➢ Some of the sedimentary basins in India have been found to have moderately high
temperatures at significant depth, where several wells may be non-flowing and/or
abandoned. The Geothermal potential from such wells can be harnessed by traditional two
well systems or a single well system. In order to assess the Geothermal potential, design and
develop a Geothermal plant, based on the dynamic modelling, OEC has identified areas in
Gandhar oil field and in Pakahjan oil field in Gujarat.
➢ Different petro-physical parameters have been calculated with thermal conductivity as final
result taking input from well logging data. Based on seismic profiles, stratigraphy from wells
and contour maps, a geological structural model has been built for the selected area. Regional
temperature model (3D) was created depicting an overview of steady state temperature of
➢ Dynamic modeling results of Gandhar and Pakahjan oil field indicated the radius of influence
to be less than 1 km around injection well, and the reservoir has the capacity to sustain a
long-time heat production for 30 years. As drilling of wells is the most significant component
of a Geothermal project cost, in order to reduce the initial development cost, OEC has
identified some of the non-flowing/abandoned oil that can be re-used for geothermal
application in Gandhar area of Cambay Basin.
Solar Thermal Energy
➢ Solar Thermal Dish Stirling Engine system installed in SECSolar dishes can be used to capture
and concentrate direct normal radiation from Sun and coupled with Stirling Engine to convert
6. the concentrated heat into electricity. Stirling engine is considered to be one of the most
efficient heat engines. One of the advantages of this method is that no water is required,
hence can be used in water deficient areas as well. Three units of Solar Thermal Dish Stirling
Engine System, developed by a US company, which can generate grid quality AC electricity
(230V, 50 Hz), up to 3 kW peak power at solar insolation of 850 W/m2, are installed &
operational in the campus of National Institute of Solar Energy (NISE), Ministry of New and
Renewable Energy, Gurugram. Each unit is producing up to 2.2 kW at 750 W/m2 in isolation.
The long-term performance evaluation of these units is in progress for more than five years.
➢ OEC is working with IIT Bombay on design and development of single cylinder free piston
Stirling engine (FPSE) for net 3 kWe electrical output using solar energy and also other
renewable energy as input. During the non-sunshine hours, it is possible to integrate biogas,
natural gas or stored heat to get power from these engines round-the-clock. This work is in
early stages of development.
➢ OEC in association with Institute of Chemical Technology, Mumbai, have develop
combinations of salts for thermal storage of heat, essential for extended utilization of solar
energy. Under this collaborative project, various salt combinations suitable for temperature
range138°C to 750°C have been developed.
➢ OEC is working with BARC, Mumbai to indigenously design and develop a 2 MWe Beam Down
Concentrated Solar Thermal Power Plant. The plant construction at Mehsana (Gujarat) is
expected to start soon. The molten salt compositions developed jointly with ICT are also to
be tested at this facility.
Biotechnology in Energy
➢ OEC has taken initiatives to develop Biotechnology Processes for Generation of Gaseous and
Liquid Fuels from various sources like Lignite, unrecovered Oil, and Coal etc. To carry out
experimental work on various research activities relating to microbial processes, OEC has set
up laboratory facilities at Delhi and Dehradun; for initial testing, characterization and
modeling (Delhi) and experimental work (Dehradun) for some of the R&D projects in
➢ It is estimated that a significant quantity of oil remains unrecovered in mature fields due to
various reasons. One of the probable approaches is to convert the unrecovered reservoir oil
to methane gas in-Situ by using bio conversion methods with the help of microorganisms.
Under this project thermophillic, anaerobic methanogenic bacterial, consortium, capable of
producing methane gas using oil as carbon substrate are to be isolated. Experiments have
Kinetic Hydro Power:
➢ There are opportunities to generate electric power using kinetic energy available in any flowing water
stream, without construction of dams or barrages for storage of water. Floating turbines can be used
to harness the kinetic energy of flowing streams of rivers, canals or tail-race of existing dams to
generate electricity for powering un-electrified homes as well as meeting the distributed power
requirement for agriculture and industrial applications. OEC is working on design and development of
kinetic hydro power generating system.
➢ In addition, OEC is also working on conversion of CO2 to value added products, recovery of oil from
oil sludge and its safe disposal etc.
➢ HOI Block
➢ Geophysical Data Processing & Interpretation Centre (GEOP1C)
➢ Block Resource Group Block
➢ ERD Block
➢ Science and Technology Block
➢ Support Services Block
➢ Institute of Drilling Technology
8. DAY 2
• Visit to GEOPIC labs
• Geo-Chemistry Lab:
• Micro Biology Lab:
➢ GEOPIC at Dehradun was established in 1987 to cater to the specialized needs of seismic data
processing and interpretation of ONGC. It is the largest computing facilities with dedicated
state-of-the art infrastructure and specialists in the fields of seismic data processing,
geoscientific data interpretation, and software development. Land and marine seismic data
of ONGC is processed and interpreted synergistically at this centre to unravel the structural
and stratigraphic complexities of the subsurface. GEOPIC processes one of the finest
capabilities in the world in the area of data evaluation, as is evident from its success rate of
54% for exploratory wells.
➢ The Vision & Mission:
To become a global player in providing geoscientific solutions to E&P problems. GEOPIC’s
mission is the computer aided exploration and reservoir description by integrating seismic
with other geoscientific data.
Different Sensors used in Geo-Chemistry Lab:
➢ A chemical sensor uses capacitive readout cantilevers and electronics to analyze a
transmitted signal. This sensor is sensitive enough to detect a single chemical or biological
molecule. Generally, chemical sensors are used to detect very small amounts of chemical
vapors. Different types of detection elements, such as carbon nanotubes, zinc oxide
nanowires, or palladium nanoparticles can be used as chemical sensors. These detection
elements change their electrical characteristics, such as resistance or capacitance once they
absorb a gas molecule. Due to the small size of the detection elements, only a few gas
molecules are sufficient to change the electrical properties of the sensing elements allowing
for high sensitivity and selectivity. The conducting properties of the nanotube change when
chemicals in the surrounding environment bond to the tube. The absorbed molecules can act
as dopants, shifting the energy of the nanotube. Similarly, the bonds formed between
absorbed chemicals and the nanotube change the band structure of the tube.
➢ MWCNTs synthesized under ambient conditions and coated with SnO2 were investigated as
sensitive elements in a sensor that exhibited fast responses to liquefied petroleum gas (LPG)
and ethanol (C2H5OH) with a recovery time of only a few seconds. A thiol functionalized
MWCNT-based chemical sensor was designed and developed for the detection of the first
four fundamental aliphatic hydrocarbons: methanol (CH3OH), ethanol (C2H5OH), propanol
(C3H7OH), and butanol (C4H9OH). High degrees of selectivity and sensitivity up to a detection
concentration of 1 ppm have been demonstrated.
9. Fuel Quality Sensor:
Quality Shield is an integrated tuning fork sensor that will directly and simultaneously measure
the viscosity, density, dielectric constant, temperature of fuels. Relying on patented tuning fork
technology, the sensor monitors the direct and dynamic relationship between multiple physical
properties to determine the quality, condition and contaminant loading of fuels such as diesel
biodiesel, gasoline, Jet fuel, kerosene, biodiesel concentration and urea quality. The multi-
parametric analysis capability improves fluid characterization algorithms. Quality Shield provides
in-line monitoring of fluids for a wide range of applications including fuel tanks, process lines and
pressurized high flow conduits. A digital serial compliant protocol provides easy to connect
interface to Consoles controller.
Factors it measures:
➢ Fuel Density
➢ Fuel Viscosity
➢ Fuel Dielectric constant
➢ Level and Water interface with multi-parametric calculation
➢ Density solution for retail and depots automation
➢ Real time fuel quality
➢ Biodiesel in diesel concentration
➢ Anti-crossover fuels detection
➢ Sump and interstitial sensors with liquid discriminating
(empty status / type of fuel / water).
OEC has taken initiatives to develop Biotechnology Processes for Generation of Gaseous and
Liquid Fuels from various sources like Lignite, unrecovered Oil, and Coal etc. To carry out
experimental work on various research activities relating to microbial processes, OEC has set up
laboratory facilities at Delhi and Dehradun; for initial testing, characterization and modelling
(Delhi) and experimental work (Dehradun) for some of the R&D projects in biotechnology.
It is estimated that a significant quantity of oil remains unrecovered in mature fields due to
various reasons. One of the probable approaches is to convert the unrecovered reservoir oil to
methane gas in-Situ by using bio conversion methods with the help of microorganisms. Under
this project thermophillic, anaerobic methanogenic bacterial, consortium, capable of producing
methane gas using oil as carbon substrate are to be isolated.
India is world’s third largest producer of coal. The reserves in India are estimated at around
298.94 billion tons, as on 31.03.2013. As per Directorate General of Hydrocarbons (DGH)
database, India has estimated 92 Trillion Cubic Feet of Coal Bed Methane (CBM) gas reserves,
however commercial production of CBM is still at a very nascent stage in the country. ONGC is
currently operating in four CBM Blocks i.e., Jharia, Bokaro, North Karanpura and Raniganj. It is
estimated that on an average only 15-20% of the coal is recoverable and rest of it lies unexploited.
The utilization of biotechnological processes can be one of the promising approaches to convert
10. low rank or unrecoverable coal into methane. It is recognized that methane generating bacteria
can act on coal seams to produce biogas, comprising mainly methane and carbon dioxide gas.
OEC in association with TERI has developed and demonstrated the microbial process for
enhancement of gas in CBM well at Jharia. The Microbial and stable gas isotope analysis data
support the stimulation of microbial communities and in-situ biological gas production. The field
experiments have demonstrated that there is many fold increase in gas production and the
enhanced activity of methanogens leads to additional/enhanced methane generation in coal
Therefore, microbially stimulated CBM can increase the longevity and productivity of the CBM
fields. R&D projects on microbial oil production from oleaginous yeast have been taken up at
R&D facilities at Dehradun. Proof of Principle experiments have established microbial conversion
of oil to gas. The process is currently under optimization for scale up experiments.
Huff and Puff Method:
The Huff and Puff method refers to discharging and shutting in the well, at most every 2-3 days
and repeated many times until the well discharge has improved and has become commercially
viable to produce. If the well will not discharge by itself, either an air compressor or a injecting
two-phase through a nearby well is used to initiate the flow.
11. DAY 3
• Visit to ERD labs
• Optical Lab
• Petro-physics Lab
An optical fiber or optical fibre is a flexible, transparent fiber made by drawing glass (silica) or
plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often
as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic
communications, where they permit transmission over longer distances and at higher
bandwidths (data rates) than electrical cables. Fibers are used instead of metal wires because
signals travel along them with less loss; in addition, fibers are immune to electromagnetic
interference, a problem from which metal wires suffer excessively. Fibers are also used for
illumination and imaging and are often wrapped in bundles, so they may be used to carry light
into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers
are also used for a variety of other applications, some of them being fiber optic sensors and fiber
Sensors using Optical Fibre used to measure pressure and temperature during
Pressure measurement using Optical Sensors:
• Mainly three technologies are presently commercially available for pressure measurement
with fiber-optic sensors: intensity-based, fiber Bragg gratings and Fabry-Pérot.
• Fabry-Pérot technology is the best compromise offering at affordable price a great flexibility
in terms of pressure ranges, high sensitivity and miniature size. In all cases of extrinsic F-P
pressure sensors, a reflective membrane is assembled above a vacuumed cavity with a semi-
reflective layer at its bottom forming a F-P cavity whose length is changing with pressure
flexing the membrane. The interference pattern created by the F-P cavity could be used to
measure precisely the diaphragm deflection and thus the pressure changes. The light used
for F-P cavity interrogation is carried on by an optical fiber (either single or multimode) linking
the interrogator and the pressure sensor.
• If a broadband light source, such as white-light is used, the periodic pattern changes as the
interference at different wavelengths become rapidly destructive, except for the zero order
where all wavelengths are in phase. By using a Fizeau wedge that creates a linear variation of
thicknesses, a cross-correlated interference pattern could be generated in the F-P
interrogator to simplify data processing since the maximum intensity peak position then
corresponds to the exact position where the optical path difference equals the one created
at the F-P cavity.
12. Temperature measurement using Optical Sensors:
Optical FBGs have also been exploited as effective fiber thermometers and temperature-sensing
devices. The fundamental principle is that the peak Bragg wavelength of an FBG shifts to longer
wavelengths as the temperature increases, and towards shorter wavelengths when the
temperature decreases. The response is linear, and its temperature sensitivity coefficient is a
function of the operating wavelength and the material’s properties of the fiber in which the FBG
is inscribed. For operation at elevated temperatures (up to 1000 8C), special fiber gratings are
needed such as those formed by regeneration techniques and IR femtosecond laser writing
techniques. Such FBGs are resistant to high temperatures and able to operate indefinitely at
elevated temperatures without risk of losing their reflectivity.
➢ Core Cutter and Grinder
The core cutter and grinder are used to resize the given core sample. Proper length and diameter
of the given core sample are basic requirements for the calculation of petro-physical properties
like porosity and permeability. This tool is provided with an electric motor which provides means
of rotation to cut the given core sample.
➢ Dean-Stark Apparatus
Dean-Stark apparatus is used to determine the water and liquid hydrocarbon contents of a core
quantitatively. The method involves direct distillation of oil from the core sample. As the core is
heated, any water present vaporizes. The water vapors are then condensed and collected in a
graduated collection tube, such that the volume of water extracted by distillation can be
measured along with volume of oil retrieved from core sample.
➢ Gas Permeameter
The Gas Permeameter measures the permeability by forcing a gas of known viscosity through
core sample of known cross section and length. Pressure, temperature and the flow of gas
through the sample are measured. A compressed inert gas such as nitrogen is recommended as
a measuring medium. The instrument follows Darcy’s Law for its operation and measurement.
➢ Helium Porosimeter
The Helium gas expansion Porosimeter enables the determination of a sample’s (1” to 1.5”
diameter) grain and pore volume via an isothermal helium expansion and the application of
Boyle’s Law and Charles’ Law. Subsequently, porosity and grain density can be calculated.
➢ Mercury Injection Capillary Pressure Apparatus
The mercury injection capillary pressure apparatus is employed for the rapid, accurate
determination of pore size distribution and capillary pressure-fluid saturation relationships in
porous media. In particular, the determination of capillary pressure curves leads to the
evaluation of connate water percentages associated with the reservoir rock. This apparatus has
a working pressure up to 2000 psi.
13. DAY 4
• Visit to ONGC Centre
• Oil Lab
• Isotopic Lab
For liquid analysis, A gas chromatograph which does Isotopic analysis was explained.
Gas chromatograph is used in many Labs of KDMIPE for different type of analysis of obtained
Most modern commercial GC systems operate in the following way
• An inert carrier gas, such as helium, is supplied from gas cylinders to the GC where the
pressure is regulated using manual or electronic (pneumatic) pressure controls the
regulated carrier gas is supplied to the inlet and subsequently flows through the column
and into the detector
As the components elute from the column they pass into a detector – where some
physicochemical property of the analyte produces a response from the detector. This response
is amplified and plotted against time – giving rise to a ‘chromatogram’
Components (such as the injection solvent) that are not retained within the column elute at the
‘dead time’ or ‘hold up time’ t0. There are various ways of measuring this parameter using
unretained compounds such as methane or hexane.
Those compounds (analytes and sample components) that are retained elute as approximately
‘Gaussian’ shaped peaks later in the chromatogram. Retention times provide the qualitative
aspect of the chromatogram and the retention time of a compound will always be the same under
14. identical chromatographic conditions. The chromatographic peak height or peak area is related
to the quantity of analyte. For determination of the actual amount of the compound, the area or
height is compared against standards of known concentration.
• Fast analysis
• High efficiency – leading to high resolution
• Sensitive detectors (ppb)
• Non-destructive – enabling coupling to Mass Spectrometers (MS) - an instrument that
measures the masses of individual molecules that have been converted into ions, i.e.
molecules that have been electrically charged
• High quantitative accuracy (<1% RSD typical)
• Requires small samples (<1 mL)
Thermal Ionization mass spectrometer:
➢ Thermal ionization mass spectrometry is a technique which has been chiefly developed for
the analysis of geological samples. The technique is used extensively for the isotope ratio
measurements required for Rb-Sr, Nd-Sm and PbTh-U geochronology studies as well as the
determination of rare-earth elements, and, less frequently, other selected elements by
isotope dilution analysis.
➢ Extensive chemical treatment of the sample, normally involving ion exchange separations, is
required before analysis, since otherwise serious isobaric interferences are observed in mass
spectra. After chemical separation, the element is loaded as a solution on to a metal filament
and is then heated under vacuum to evaporate the solvent and precondition the sample to
form an amorphous residue suitable for analysis. The filament is mounted in the sample
turret of the mass spectrometer and is pumped down to high vacuum.
➢ The sample is atomized and ionized by heating the filament to the required temperature by
passing an electric current through it. The sample must be in a suitable chemical form to
ensure that a stable positive ion beam is maintained for the duration of the analysis. Ions are
extracted into the mass analyser by applying a potential of several kilovolts (positive) to the
filament relative to an anode plate.
Radiation Type Pyrometer:
For measuring any temperature above 1200oC a radiation pyrometer type thermometer is
generally used. The main reason behind that, this type of temperature sensors or thermometer
is not required to be brought in touch with the object whose temperature to be measured. The
main working principle of this type of instruments is that, it senses the heat radiation from a
targeted hot body and reads and records its temperature, depending upon the intensity of
radiation. There are mainly two types of radiation pyrometers one is fixed focus type another is
variable focus type.
15. Fixed Focus Type Radiation Pyrometer
It mainly consists of a long tube, a concave mirror is placed at the end of the tube. A sensitive
thermocouple is placed in front of the concave mirror in such a suitable distance, that the heat
radiation which enters the tube through narrow aperture at the front end of tube, reflected by
the concave mirror and focused on the hot junction of the thermocouple. Due to this fixed
concave mirror the radiation is always focused on the thermocouple irrespective of the distance
between hot object and this instrument. This is reason for which this instrument is called fixed
focus type radiation pyrometer. The emf generated in the thermocouple is then measured with
a help of a galvanometer or millivoltmeter and this can be directly calibrated with temperature
to get temperature reading readily.
Variable Focus Type Radiation Pyrometer
The position of the concave mirror can be adjusted by adjusting knob attached to the instrument.
Due to this adjustable concave mirror, the instrument is known as variable focus radiation
pyrometer. The concave mirror made of highly polished steel. The heat rays form the targeted
hot object are first received by the concave mirror then are reflected on to the blackened thermo
junction consisting of a very small copper or silver disc to which the wires forming the junction
16. DAY 5
• Troubleshooting of Water Bath
• Troubleshooting of Furnace
WATER BATH IN OIL LAB
The water bath is an instrument used in the laboratory for carrying out agglutination,
inactivation, bio-medical and industrial incubation procedures. In general water bath is used
some application requires oil bath (PI lab). The temperature range at which water baths are
normally range between room temperature and 60 ˚C. Water baths are made of steel and are
generally covered with electrostatic paint with high adherence and resistance to environmental
The control panel has following elements-
1.The on and off control switch
2.A menu button for selecting the operation's parameters: operation temperature, alarm
temperature, temperature scale.
3. Two buttons for parameter adjustment.
4. A screen
TROUBLESHOOTING TABLE FOLLOWED BY INFOCOM GROUP FOR WATER BATH
PROBLEM PROBLEM CAUSE SOLUTION
There is no power in the
• The water bath is
• The switch is
• The fuse is defective.
• connect the water
• change the switch
• change the fuse
The water bath is not getting
• the temperature
control is not set.
• the resistors are
• the limit control is not
• set the temperature
• change the resistors
• set the limit control.
17. The temperature is higher
than that selected.
• the temperature
control is defective.
• verify the selection
• change the
temperature control if
The samples are warmed
• the tank is empty or
contains very little
• fill the tank up to
It is used for heating the samples just like oven but at a higher temperature range (1200˚C) and
uses ceramic type of insulation to avoid loss of heat. Two important elements of furnace are
heating element and thermocouple. Element life is reduced somewhat by repeated heating and
cooling. If the furnace is to be used again within a few hours, it is best to keep it at the operating
temperature of 260˚C. Thermocouple must be changed in every 6 months to a year as a
TO REPLACE THE HEATING ELEMENT-
1. Disconnect the furnace from power supply.
2. Remove the back-terminal cover of the furnace.
3. Loosen the nuts on the terminals of elements to be replaced.
4. Open the door and pull the defective element out.
5. Slide the new element into place.
6. Tighten the nuts securely. Cut off any excess lead wire.
7. Replace the back-terminal cover.
8. Reconnect furnace to power supply.
9. Test operation of furnace.
TO REPLACE THE THERMOCOUPLE-
1. Disconnect the furnace from power supply.
2. Remove both back covers.
3. Remove the clip holding thermocouple in place and remove the two screws on
4. Remove the thermocouple. Pull the thermocouple straight out of the hole in the
chamber first to avoid damage to insulation.
5. Guide looped ends of the new thermocouple through the plastic bushings with red (-)
lead to the right as you face the back of the furnace.
6. Insert the thermocouple straight through the hole in chamber.
7. Secure the thermocouple with clips and screws Connect the looped ends of the
thermocouple to terminals with +to+ yellow wire. Chrome/ alumel thermocouples and
lead wire are easily tested with a magnet. The non-magnetic wire is positive (+) and
magnetic wire is negative (-).
8. Replace both the back covers.
18. 9. Reconnect the power supply.
TO REPLACE THE SOLID-STATE RELAY -
1. Disconnect the furnace from power supply.
2. Remove the back-control cover. Remove the front control panel screws to provide
access to solid state relay. Slide control section forward.
3. Disconnect wires from terminal. Identify or mark wires.
4. Remove the nuts, washers, and screws from relay, then remove relay.
5. Install the new relay.
TROUBLESHOOTING TABLE FOR FURNACE
PROBLEM PROBABLE CAUSE SOLUTION
The power switch
does not illuminate
• The furnace is not connected
to power supply.
• ON and OFF power switch is
• Fuses blown
• Check the furnace
connection to power
• Replace power switch
• Replace fuses.
The furnace does not
heat, cycle light
• Heating element is burn out or
• Replace heating
elements or repair
The furnace does not
• No power.
• Two or more heating elements
208V or 240V furnace are
• Thermocouple has oxidized
and opened the circuit.
• Defective electrical relay
• Check power sources.
• Replace defective
• Replace relay
• Shorted thermocouple
• Shorted soli state relay
• Defective control
• Thermocouple leads are
• Check thermocouple
• Replace solid state
Slow heat up • One or two heating elements
are burned out.
• Heavy load in chamber
• Low line voltage.
• Wrong heating elements.
• Replace burned out
• lighten load in
• Install line of sufficient
size and proper
19. Repeated element
• Heavy load in chamber.
• Overheating furnace.
• Wrong heating elements.
• oxidized thermocouple
• wired improperly
• install proper
• lighten load in
• keep furnace under
• install proper
• replace thermocouple.
• check wiring.
20. DAY 6
• Visit to Electrical Repair Shop in Support Services Block
UPS (uninterrupted power supply)
UPS is an electrical apparatus that provides emergency power to a load when the input power
source or mains power fails. A UPS differs from an auxiliary or emergency power system or
standby generator in that it will provide near-instantaneous protection from input power
interruptions, by supplying energy stored in batteries, super capacitors, or flywheels. The on-
battery runtime of most uninterruptible power sources is relatively short (only a few minutes)
but enough to start a standby power source or properly shut down the protected equipment.
A UPS is typically used to protect hardware such as computers, data centres, telecommunication
equipment or other electrical equipment where an unexpected power disruption could cause
injuries, fatalities, serious business disruption or data loss. UPS units’ range in size from units
designed to protect a single computer without a video monitor (around 200 voltampere rating)
to large units powering entire data centres or buildings. The world's largest UPS, the 46-
megawatt Battery Electric Storage System (BESS), in Fairbanks, Alaska, powers the entire city and
nearby rural communities during outages.
21. Components of ups system:
➢ Mains distribution unit:
This unit is already a part of our installation. It distributes the Mains (utility) and/or Generator
power to your facility and will also supply input to your UPS system. The safety “earth”
connection for the UPS system is also considered to be a part of the Mains distribution unit.
➢ Auxiliary Module:
An Auxiliary module generally comprises a Voltage Stabilizer (static type or servo type) to provide
a stable alternate supply to the UPS.
➢ UPS Module:
Consists of the UPS (without Battery). Depending upon the configuration selected, one or more
UPS modules can be employed.
➢ Battery Module:
This module comprises the battery pack for supplying power to the UPS module in the event of
a mains failure. There are various types of batteries- SMFB (Sealed Maintenance Free Battery),
LATB, NI-CD etc. Battery module may either be in the form of an enclosure or may be supplied as
a rack. Vented batteries such as LATB can emit acidic fumes & requires a special room.
➢ Output Distribution Module:
Output of the UPS system needs to be distributed to various loads. Such a module generally
comprises switches, fuses, etc. The coordination of fuses is important to avoid faults from
affecting the other loads supported by the UPS.
The Modular UPS is an on-line, double-conversion UPS that permits operation in the following
• Normal mode
• Battery mode
• Bypass mod
• Maintenance mode (manual bypass)
➢ Normal Mode:
The inverter of power modules continuously supplies the critical AC load. The rectifier/charger
derives power from the AC mains input source and supplies DC power to the inverter while
simultaneously FLOAT or BOOST charging its associated backup battery.
➢ Battery Mode or Mains Failure:
Upon failure of the AC mains input power, the inverter of power modules, which obtain power
from the battery, supply the critical AC load. There is no interruption in power to the critical load
upon failure. After restoration of the AC mains input power, the” Normal mode” operation will
continue automatically without the necessity of user intervention.
➢ Bypass Mode or UPS failure:
22. If the inverter overload capacity is exceeded under Normal mode, or if the inverter becomes
unavailable for any reason, the static transfer switch will perform a transfer of the load from the
inverter to the bypass source, with no interruption in power to the critical AC load. Should the
inverter be asynchronous with the bypass, the static switch will perform a transfer of the load
from the inverter to the bypass with power interruption to the load. This is to avoid large cross
currents due to the paralleling of unsynchronized AC sources. This interruption is programmable
but typically set to be less than 3/4 of an electrical cycle, e.g., less than 15ms (50Hz) or less than
12.5ms (60Hz). The action of transfer/re-transfer can also be done by the command through
➢ Manual Mode:
A manual bypass switch is available to ensure continuity of supply to the critical load when the
UPS becomes unavailable e.g. during a maintenance procedure.
➢ Excellent Transient Response
➢ High Crest Factor Load Handling Capability
➢ High Fuse clearing Capability
➢ Low Noise
➢ Wide Frequency Synchronization Window
23. DAY 7
• Visit to Institute of Drilling Technology
• Preliminaries of Oil and Gas Production
PRELIMINARIES OF OIL AND GAS PRODUCTION
There are mainly four steps involved in the production of crude oil and gas. They are:
➢ 1. Exploration
➢ 2. Gas and Crude Oil Production
➢ 3. Processing
➢ 4. Transportation.
➢ Exploration means a scientific search set by the geologists and geophysicists for locating
the probable regions of oil and gas. In general terms this refer to the entire gamut of
search for hydrocarbons with the help of geological and geophysical surveys integrated
with laboratory data backup, selection of suitable locations of exploratory test-drilling
and testing of such wells.
➢ Geophysical technology greatly reduces the risk of drilling. Wells are drilled to test a
geological theory or model that is generated in the Wide Area Geological Review and
validated by seismic data. The relative position of rock layers can be imaged from the
patterns of acoustic sound waves that are reflected from subsurface formations. For two-
dimensional (2D) seismic operations, field crews run parallel lines of sound recorders at
wide intervals to cover large areas in a relatively inexpensive manner. Once a field is
discovered, 3D seismic can be run in a grid pattern with close sound recorders to delineate
the most attractive places to drill additional wells and determine the areal extent of a
GAS AND CRUDE OIL PRODUCTION:
➢ According to generally accepted theory, Crude Oil is derived from ancient biomass. It is a
fossil fuel derived from ancient fossilized organic materials. More specifically, crude oil
and natural gas are products of heating of ancient organic materials (i.e. kerogen) over
geological time. Three conditions must be present for oil reservoirs to form: a source
rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it
into oil; a porous and permeable reservoir rock for it to accumulate in; and a cap rock
(seal) or other mechanism that prevents it from escaping to the surface. Within these
reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of
water below the oil layer and a layer of gas above it according to their densities, although
the different layers vary in size between reservoirs. Because most hydrocarbons are
lighter than rock or water, they often migrate upward through adjacent rock layers until
either reaching the surface or becoming trapped within porous rocks (known as
reservoirs) by impermeable rocks above. However, the process is influenced by
24. underground water flows, causing oil to migrate hundreds of kilometres horizontally or
even short distances downward before becoming trapped in a reservoir. When
hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be
extracted by drilling and pumping.
Offshore productions consist of several operations that allow the safe and efficient production
of hydrocarbons from the flowing wells. The key operations that will be conducted at the offshore
➢ Produced Hydrocarbon Separation
➢ Gas Processing
➢ Oil and Gas Export
➢ Well Testing
➢ Produced Water Treatment and Injection
➢ Utilities to support these processes
➢ The gas pipeline is fed from the High-Pressure compressors. Oil pipelines are driven by
separate booster pumps. For longer pipelines, intermediate compressor stations or pump
stations will be required due to distance or crossing of mountain ranges.
25. DAY 8
• Visit to Institute of Drilling Technology
• Information on Drilling Process
A major difference between onshore and offshore drilling is the nature of the drilling platform.
In addition, in offshore drilling the drill pipe must pass through the water column before entering
the lake or seafloor. Offshore wells have been drilled in waters as deep as 10,000 ft (305 m).
➢ Offshore drilling requires the construction of an artificial drilling platform, the form of
which depends on the characteristics of the well to be drilled. Offshore drilling also
involves the use of a drilling template that helps to connect the underwater drilling site
to the drilling platform located at the water’s surface. This template typically consists of
an open steel box with multiple holes, depending on the number of wells to be drilled.
The template is installed in the floor of the water body by first excavating a shallow hole
and then cementing the template into the hole. The template provides a stable guide for
accurate drilling while allowing for movement in the overhead platform due to wave and
➢ There are two types of basic offshore drilling platforms, the movable drilling rig and the
permanent drilling rig. The former is typically used for exploration purposes, while the
latter is used for the extraction and production of oil and/or gas. A variety of movable rigs
are used for offshore drilling. Drilling barges are used in shallow (<20 ft [<6 m] water
depth), quiet waters such as lakes, wetlands, and large rivers. As implied by the name,
drilling barges consist of a floating barge that must be towed from location to location,
with the working platform floating on the water surface. In very shallow waters, these
may be sunk to rest on the bottom. They are not suitable for locations with strong
currents or winds and strong wave action. Like barges, jack-up rigs are also towed, but
once on location three or four legs are extended to the lake bottom while the working
platform is raised above the water surface; thus, they are much less affected by wind and
water current than drilling barges.
➢ Several types of drilling techniques are currently employed in oil and gas drilling: straight
hole drilling, directional drilling, horizontal drilling, air drilling, and foam drilling.
Regardless of the drilling technique, a well is typically drilled in a series of progressively
➢ Straight Hole Drilling
o In straight hole drilling, the well bore is vertical and deviates by no more than 3
degrees anywhere along the well bore, and the bottom of the well deviates by no
26. more than 5 degrees from the starting point of the well bore at the drilling
platform. With straight hole drilling, the drill bit may be deflected if it contacts
fault zones or dipping beds of hard rock layers.
➢ Directional and Horizontal Drilling
o Directional drilling (also termed slant drilling) involves the drilling of a curved well
to reach a target formation. Directional drilling is employed when it is not possible,
practicable, or environmentally sounds to place the drilling rig directly over the
target area. Directional drilling is especially useful for offshore locations. With
directional drilling, it may take several thousand feet for the well to bend from
drilling vertically to horizontally.
Directional and Horizontal drilling
➢ Once a well has been drilled and verified to be commercially viable, it must be completed
to allow for the flow of oil or gas. The completion process involves the strengthening of
the well walls with casing and installing the appropriate equipment to control the flow of
oil or gas from the well. Casing consists of a stacked series of metal pipes installed into
the new well to strengthen the walls of the well hole, to prevent fluids and gases from
seeping out of the well as it is brought to the surface, and to prevent other fluids or gases
from entering the rock formations through which the well was drilled.
27. DAY 9
• Visit to Satellite Station
• Information on Satellite Communication System
In general, a satellite in anything that orbits something else, for example, the moon orbits the
Earth. In a communications context, satellite is a specialized wireless receiver/transmitter that is
launched by a rocket and placed in orbit around the earth. There are hundreds of satellites
currently in operation. They are used for such diverse purposes as weather forecasting, television
broadcast amateur radio communications, Internet communications, and the Global Positioning
➢ Satellites are specifically made for telecommunication purpose. They are used for mobile
applications such as communication to ships, vehicles, planes, hand-held terminals and for
TV and radio broadcasting
➢ They are responsible for providing these services to assigned region area on the Earth. The
power and bandwidth of these satellites depend upon the preferred size of the footprint
complexity of the traffic control protocol schemes and the cost of ground stations.
➢ A satellite works most efficiently when the transmissions are focused with a desired area.
When the area is focused, then the emissions don go outside that designated area and thus
minimizing the interference to the other system. This leads more efficient spectrum usage.
Components of Satellite Communication:
Satellite communication has two main components:
1. Ground segment, which consists of fixed or mobile transmission reception, and ancillary
2. Space segment, which primarily is the satellite itself. A typical satellite link involves the
transmission or up linking of a signal from an Earth station to a satellite. The satellite then
receives and amplifies the signal and retransmits it back to Earth, where it is received and
preamplifier by Earth stations and terminals, Satellite receivers on the ground include direct to
home (DTH) satellite equipment, mobile reception equipment in aircraft, satellite telephones and
SPACE SEGMENT PAYLOAD
Equipment satellite needs to do its job. Include antennas, cameras, radar and electronics. Payload
is different for every satellite. For example payload for a weather satellite includes cameras while
payload for a communication satellite includes antennas.
Part or the satellite that carries the payload and its equipment into space. It holds all the satellite
parts together and provides electrical power, computers, and propulsion to the space. It also
contains equipment that allows the satellite to communicate with Earth.
28. TT&C SUBSYSTEM:
The telemetry, tracking, and command subsystem performs several routine functions aboard the
spacecraft. The telemetry, or telemetering, function could be interpreted as measurement
distance Specifically, it refers to the overall operation of generating an electrical signal
proportional to the quantity being measured and encoding and transmitting this to a distant
station, which for the satellite is one of the earth stations. Data which are transmitted as
telemetry signals includes attitude information such as that obtained from sun and earth sensors:
environmental information as the magnetic field intensity and direction, the frequency of
meteorite impact, and so on and spacecraft Information such as temperatures, power supply
voltages, and stored-fuel pressure.
A transponder is a wireless communications, monitoring or control device that pick up and
automatically responds to an incoming signal. The term is a contraction of the words transmitter
and responder Transponders can be either passive or active.
Passive transponder allows a computer or robot to identify an object. Man labels, such as those
on credit cards and store items are common examples. A passive transponder must be used with
an active Sensor that decodes and transcribes the data the transponder contains.
Active transponders are employed in location, identification, and navigation systems for
commercial and private aircraft. An example is an RFID(radio-frequency identification device that
transmits a coded signal when it receives a request from a monitoring or control point.
The ground segment is a network of earth stations and user terminals that provides applications
and services to end users. Each network requires: A central point of management and control. A
means to connect distant users to sources of content or other networks, such as the Internet.
Because the ground segment is often provided separately from the space segment, particularly
for satellites like Horizons-1 and 2, the operator of the ground segment usually purchases the
29. DAY 10
• Visit to Satellite Station
• Information on GSAT-10
ONGC uses gsat-10 satellite
Frequency band allocation:
➢ For receiver:3907MHz- 3943MHz
➢ Center freq. for Rx:3925 MHz
➢ For tx:6132-6168 MHz
➢ Center freq. for tx:6150 MHz
GSAT-10, India's advanced communication satellite is a high power satellite being inducted into
the INSAT system. Weighing 3400 kg at lift-off, GSAT-10 is configured to carry 30 communication
transponders in normal C-band, lower extended C-band and Ku-hand as well as a GPS Aided GEO
Augmented Navigation (GAGAN) payload operating in L1 and 1.5 band. GSAT.10 is the second
satellite to carry (GAGAN) payload after GSAT-8, which is already providing navigation services
from the satellite orbit. GSAT-10 also carries a Ku-band beacon to help in accurately pointing
ground antennas towards the satellite. The 30 communication transponders on-board GSAT-10
will further augment the capacity in the INSAT system. The GAGAN payload provides the Satellite
Based Augmentation System (SBAS), through which the accuracy of the positioning information
obtained from the GPs satellite is improved by network of ground based receivers and made
available to the users in the country through geo- stationary satellites
PAYLOADS OF GSAT-10 COMMUNICATION PAYLOADS
12 Ku-hand transponders each with 36 Mhz usable bandwidth employing 140 W Travelling Wave
Tube Amplifier (TWTA) with footprint covering Indian mainland with an Edge of Cover Effective
isotropic Radiated Power (EIRP) of 51.5 dBW and Andaman & Nicobar islands with an EIRP of 49.5
dBW 12 C-band transponders each with 36 Mhz usable bandwidth employing 140 W TWTA with
footprint covering Indian mainland and West Asia with an Edge of Coverage EIRO of 40 dBW 6
Lower Extended C-band Transponders each with 36 MHz usable bandwidth employing 32
WTWTA with footprint covering Indian mainland and island territories with an Ede of Cosen EIRP
of 38 dB W and 37 dB W respectively.
Two-channel GAGAN payload operating in L1 and L5 bands provides Satellite-based Navigation
services with accuracy and integrity required for civil aviation applications over Indian Air Space
30. FREQUENCY ALLOCATION FOR SATELLITE
1. Allocation of frequencies to satellite services is a complicated process which requires
international coordination and planning. This is done as per the International Telecommunication
Union (ITU). To implement this frequency planning, the world is Divided into the regions.
➢ Region1: Europe, Africa and Mongolia
➢ Region 2: North and South America and Greenland
➢ Region 3: Asia .
➢ Region 4:Australia and southwest Pacific
2. Within these regions, the frequency bands are allocated to various satellite services. Some of
them are listed below.
➢ Fixed satellite Service Provides Links for existing Telephone Networks Used for
transmitting television signals to cable companies.
➢ Broadcasting satellite service Provides Direct Broadcast to homes. Eg Live Cricket
➢ Mobile satellite services: This includes services for Land Mobile, Maritime Mobile and
Below are the frequencies allocated to these satellites:
Frequency Band (GHZ) Designations:
➢ VHF: 0.1-0.3
➢ UHF: 0.3-1.0
➢ L-band: 1.0-2.0
➢ S-band: 2.0-4.0
➢ C-band: 4.0-8.0
➢ X-band: 8.0-12.0
➢ Ku-band: 12.0-18.0 (Ku is Under K Band)
➢ Ka-band: 18.0-27.0 (Ka is Above K Band)
➢ V-band: 40.0-75.0
➢ W-band: 75-110
➢ Mm-band: 110-300
➢ um-band: 300-3000
"ONGC SATELLITE OPERATIONS ARE DONE IN C BAND i.e. (4-8 GHz)
Based on the satellite service, following are the frequencies allocated to the satellites
Frequency Band (GHZ) Designations:
VHF: 0.1-0.3 Mobile & Navigational Satellite Services
L-band: 1.0-2.0 Mobile & Navigational Satellite Services
C-band: 4.0-8.0 Fixed Satellite Service
Ku-band: 12.0-18.0 Direct Broadcast Satellite Services
31. DAY 11
• Block Diagram and Applications
Block Diagram of Satellite communication system
1.Users are the ones who generate baseband signals, which is processed all the earth station and
then transmitted to the satellite through dish antennas.
2. Now the user is connected to the Earth station via some telephone switch or some dedicated
3. The satellite receives the uplink frequency and the transponder present inside the satellite
does the processing function and frequency down conversion in order to transmit the downlink
signal at different frequency
4. The earth station then receives the signal from the satellite through parabolic dish antenna
and processes it to get back the baseband signal
5. This baseband signal is then transmitted to the respective user via dedicated link or other
terrestrial system. Previously satellite communication system used large sized parabolic antennas
with diameters around 30 meters because of the very faint and weak signals received. The earth
station antennas are now not large in size as the antennas used in olden days.
Applications of Satellite:
Certain satellites are specifically designed to monitor the climatic conditions of earth. They
continuously monitor the assigned areas of earth and predict the weather of that region. This is
done by taking images of earth from the satellite. These images are transferred using assigned
Earth Station Earth Station
Terrestrial System Terrestrial System
32. radio frequency to the earth station (Earth Station: it's a radio station located on the earth and
used for relaying signals from satellites. These satellites are exceptionally useful in predicting
disasters like hurricane, and monitor the changes in the Earth's vegetation, sea state, ocean color
and ice fields.
These dedicated satellites are responsible for making 100’s of channels across the globe available
for everyone. They are also responsible for broadcasting live matches news and world wide radio
These satellites are often used for gathering intelligence as a communications satellite used for
military purposes, or as a military weapon. A satellite by itself is neither military nor civil. It is the
kind of payload it carries that enables one to arrive at a decision regarding its military or civilian
The system allows for precise localization world-wide, and with some additional techniques the
precision is in the range of some meters. Ships and aircraft rely on GPS as an addition to
traditional navigation systems. Many vehicles come with installed GPS receivers.
One of the first applications of satellites for communication the establishment of international
telephone backbones. Instead of using cables it was sometimes faster to launch new satellite.
But, fiber optic cables are still replacing satellite communication across long distance as in fiber
optic cable light is used instead of radiofrequency hence making the communication much faster
Connecting Remote Areas
Due to their geographical location many places all over the world do not have direct wired
connection to the telephone network or the internet because of the current state of the
infrastructure of a country. Here the satellite provides a complete coverage and (generally) there
is one satellite always present across a horizon.
33. DAY 12
• Introduction to Solar Energy
• Potential of Solar Energy
• Construction of Solar Panels
(A) Conventional Energy Sources:
The energy sources which cannot be compensated, once these are used (after their exploitation)
are termed as conventional energy sources.
Some important conventional energy sources are discussed below:
Coal is a major conventional energy sources. It was formed from the remains of the trees and
ferns grew in swamps around 500 million years ago. The bacterial and chemical decomposition
of such plant debris (which remained buried under water or clay) produced an intermediate
product known as peat which is mainly cellulose (C6H10O5)n. Due to progressive decomposition
by heat and pressure, the cellulose lost moisture H2 and Oz and got converted in to coal as per
the given equation
The average formula of coal is (C3/H4/)n. Out of the 6000 billion tons coal stocks under earth crust,
200 tons have been exploited the present society. The coal reserves are found in the states like
Jharkhand, Orissa, West Bengal, M.P. and A.P. Some important coal fields are: Talcher, Raniganj,
Jharia, Bokaro, Panch Konkam, Signoulli, Chanda etc.
2. Petroleum and natural gases:
Petroleum is a complex mixture of hydrocarbons, mostly alkanes and cycloalkanes. It occurs
below the earth crust entrapped under rocky strata. In its crude form, the viscous black liquid is
known as petroleum and a gas in contact with petroleum layer which flows naturally from oil
wells is termed as natural gases. The composition of natural gas is a mixture of mainly methane,
(95.0%), small amounts of ethane, propane and butane (3.6%) and traces of CO2 (0.48%) and
A liquid mixture of propane and butane can be obtained from natural gas or refinery gases at
room temperature under a pressure of 3-5 atmosphere. This is stored and distributed in 40-100
litre capacity steel cylinders.
34. The crude petroleum after being refined and purified, are available as petrol, diesel, kerosene,
lubricating oil, plastic etc. for commercial and domestic use. In India, the oil deposits, are found
at Ganga-Brahmaputra Valley, Bombay high, plains of Gujarat, Thar desert of Rajasthan and area
around Andaman Nicobar Islands.
On the world basis, petroleum deposits are found at Saudi Arab, Iraq, Iran, Kuwait, USA, Mexico,
Russia etc. As per the current survey, it is found that world petroleum deposits are diminishing
at a very faster rate. If preventive steps are not taken, the existing petroleum will be available
maximum up to 40 years.
3. Fuel woods:
The rural peoples require fuel wood or fire Wood for their day to day cooking which are obtained
from natural forests and plantations. Due to rapid deforestation, the availability of fire wood or
fuel wood becomes difficult. This problem can be avoided by massive afforestation (plantation)
on degraded forest land, culturable waste land, barren land grazing land etc.
Energy obtainable from water flow or water falling from a higher potential to lower potential, is
known is hydro- power. It is a conventional and renewable form of energy which can be
transmitted to long distance through cables and wires.
In India, hydroelectric power is generated by a number of multipurpose river valley projects e.g.
Hydro-power project Hirakud, Bhakra Mangal project, Narmada valley project, Nagarjun Sagar
project, Sardar Sarovar project etc.
5. Nuclear energy:
A small amount of radioactive substance (U235) can produce a lot of energy through the process
of nuclear fission. For example, one ton of uranium can provide energy which is much higher than
three million tons of coal or 12 million barrels of oil. In order to obtain nuclear energy, nuclear
reactors are required. There are around 300 nuclear reactors all over the world. India has only
four nuclear power stations (reactors).
The nuclear energy can be used in production of electrical energy, as a fuel for marine vessel and
space crafts and for the generation of heat in chemical processing plants. In India, Uranium
deposits are found at different parts of Rajasthan and Singhbum of Jharkhand.
Thorium is recovered from monazite sand found in the state of Kerala. Due to the higher energy
releasing tendency of these radioactive substances, these can be used in nuclear reactors to
release energy crisis. But the radioactive substances are exhaustible and can be used to develop
nuclear weapons of mass destruction. In addition, dumping or radioactive wastes cause serious
35. (B) Non-conventional energy sources:
The conventional energy sources discussed above are exhaustible and in some cases, installation
of plants to get energy is highly expensive. In order to meet the energy demand of increased
population, the scientists developed alternate nonconventional natural Resources sources of
energy which should be renewable and provide a pollution free environment.
Some nonconventional, renewable and inexpensive energy sources are described below:
1. Solar energy:
Solar energy, a primary energy source, is non-polluting and inexhaustible.
There are three methods to harness solar energy:
(i) Converting solar energy directly into electrical energy in solar power stations using photo cells
or photovoltaic cells or silicon solar cell.
(ii) Using photosynthetic and biological process for energy trapping. In the process of
photosynthesis, green plants absorb solar energy and convert it into chemical energy, stored in
the form of carbohydrate.
(iii) Converting solar energy in to thermal energy by suitable devices which may be subsequently
converted into mechanical, chemical or electrical energy.
Since solar energy is non-ending and its conversion to some other energy form is nonpolluting,
attention should be paid for the maximum utilization of solar energy.
2. Wind energy:
Wind is air in motion. The movement of air takes place due to the convection current set out in
the atmosphere which is again due to heating of earth’s surface by solar radiation, rotation of
earth etc. The movement of air occurs both horizontally and vertically.
The average annual wind density is 3 kW/m2/day along costal lines of Gujarat, western ghat
central parts of India which may show a seasonal variation (i.e., in winter it may go up to
Since wind has a tremendous amount of energy, its energy can be converted into mechanical or
electrical energy using suitable devices, now days, wind energy s converted in to electrical energy
which is subsequently used for pumping water, grinding of corns etc. As per available data dearly
20,000 mW of electricity can be generated from wind. In Puri, wind farms are set up which can
generate 550 kW of electricity.
3. Tidal energy:
The energy associated with the tides of the Ocean canbe converted in to electrical energy. France
constructed the first tidal power plant in 1966. India could take up Ocean thermal energy
conversion (OTEC) and by the process it will be capable of generating 50,000 mW of electricity,
to meet the power requirements of remote oceanic islands and coastal towns. The Netherlands
is famous for windmills. In India, Gujarat and Tamilnadu have windmills. The largest wind farm
has been set at Kanyakumari which generates 380 mW of electricity.
4. Geothermal energy:
The geothermal energy may be defined as the heat energy obtainable from hot rocks present
inside the earth crust. At the deeper region of earth crust, the solid rock gets melted in to magma,
due to very high temperature. The magma layer is pushed up due to some geological changes
36. and get concentrated below the earth crust. The places of hot magma concentration at fairly less
depth are known as hot spots.
These hot spots are known as sources of geothermal energy. Now a day, efforts are being made
to use this energy for generating power and creating refrigeration etc. There are a quite few
number of methods of harnessing geothermal energy. Different sites of geothermal energy
generation are Puga (Ladakh), Tattapani (Suraguja, M.P.), Cambay Basin (Alkananda Valley,
5. Bio-mass based energy:
The organic matters originated from living organisms (plants and animals) like wood, cattle dung,
sewage, agricultural wastes etc. are called as biomass. These substances can be burnt to produce
heat energy which can be used in the generation of electricity. Thus, the energy produced from
the biomass is known as biomass energy.
There are three forms of biomass:
(i) Biomass in traditional form:
Energy is released by direct burning of biomass (e.g. wood, agricultural residue etc.)
(ii) Biomass in nontraditional form:
The biomass may be converted in to some other form of fuel which can release energy. For
example, carbohydrate can be converted into methanol or ethanol which may be used as a liquid
(iii) Biomass for domestic use:
When organic matters like cow dung, agricultural wastes, human excreta etc. subjected to
bacterial decomposition in presence of water in absence of air, a mixture of CH4, C02, H2, H2S etc.
is produced. These gases together are known as biogas. The residue left after the removal of
biogas is a good source of manure and biogas is used as a good source of non-polluting fuel.
Biogas is an important source of energy to meet energy, requirements of rural area. As per given
data, around 22,420-million m3 of gas can be produced from the large amount of cow dungs
obtained in rural areas in a year. The gas is generated by the action of bacteria on cow dung in
absence of air (oxygen). There are two types of biogas plants namely. Fixed done type and
floating gas holder type.
37. Solar energy:
➢ Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-
evolving technologies such as solar heating, photovoltaics, solar thermal energy, solar
architecture, molten salt power plants and artificial photosynthesis.
➢ It is an important source of renewable energy and its technologies are broadly characterized
as either passive solar or active solar depending on how they capture and distribute solar
energy or convert it into solar power. Active solar techniques include the use of photovoltaic
systems, concentrated solar power and solar water heating to harness the energy. Passive
solar techniques include orienting a building to the Sun, selecting materials with favorable
thermal mass or light-dispersing properties, and designing spaces that naturally circulate air.
➢ The large magnitude of solar energy available makes it a highly appealing source of electricity.
The United Nations Development Programme in its 2000 World Energy Assessment found
that the annual potential of solar energy was 1,575–49,837 exajoules (EJ). This is several times
larger than the total world energy consumption, which was 559.8 EJ in 2012.
➢ The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper
atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by
clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly
spread across the visible and near-infrared ranges with a small part in the near-ultraviolet.
Most of the world's population live in areas with insolation levels of 150–300 watts/m², or
3.5–7.0 kWh/m² per day.
➢ Solar radiation is absorbed by the Earth's land surface, oceans – which cover about 71% of
the globe – and atmosphere. Warm air containing evaporated water from the oceans rises,
causing atmospheric circulation or convection. When the air reaches a high altitude, where
the temperature is low, water vapor condenses into clouds, which rain onto the Earth's
surface, completing the water cycle. The latent heat of water condensation amplifies
convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones.
Sunlight absorbed by the oceans and land masses keeps the surface at an average
temperature of 14 °C. By photosynthesis, green plants convert solar energy into chemically
stored energy, which produces food, wood and the biomass from which fossil fuels are
derived. The total solar energy absorbed by Earth's atmosphere, oceans and land masses is
approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour
than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in
biomass. The amount of solar energy reaching the surface of the planet is so vast that in
one year it is about twice as much as will ever be obtained from all of the Earth's non-
renewable resources of coal, oil, natural gas, and mined uranium combined.
Photovoltaic solar panels absorb sunlight as a source of energy to generate electricity. A
photovoltaic (PV) module is a packaged, connected assembly of typically 6x10 photovoltaic solar
cells. Photovoltaic modules constitute the photovoltaic array of a photovoltaic system that
generates and supplies solar electricity in commercial and residential applications.
38. Each module is rated by its DC output power under standard test conditions (STC), and typically
ranges from 100 to 365 Watts (W). The efficiency of a module determines the area of a module
given the same rated output – an 8% efficient 230 W module will have twice the area of a 16%
efficient 230 W module. There are a few commercially available solar modules that exceed
efficiency of 24%. A single solar module can produce only a limited amount of power; most
installations contain multiple modules. A photovoltaic system typically includes an array of
photovoltaic modules, an inverter, a battery pack for storage, interconnection wiring, and
optionally a solar tracking mechanism. The most common application of solar panels is solar
water heating systems. The price of solar power has continued to fall so that in many countries
it is cheaper than ordinary fossil fuel electricity from the electricity grid, a phenomenon known
as grid parity.
Theory and construction
Photovoltaic modules use light energy (photons) from the Sun to generate electricity through the
photovoltaic effect. The majority of modules use wafer-based crystalline silicon cells or thin-
film cells. The structural (load carrying) member of a module can either be the top layer or the
back layer. Cells must also be protected from mechanical damage and moisture. Most modules
are rigid, but semi-flexible ones based on thin-film cells are also available. The cells must be
connected electrically in series, one to another. Externally, most of photovoltaic modules use
MC4 connectors type to facilitate easy weatherproof connections to the rest of the system.
Module electrical connections are made in series to achieve a desired output voltage or in parallel
to provide a desired current capability. The conducting wires that take the current off the
modules may contain silver, copper or other non-magnetic conductive transition metals. Bypass
diodes may be incorporated or used externally, in case of partial module shading, to maximize
the output of module sections still illuminated.
Some special solar PV modules include concentrators in which light is focused by lenses or
mirrors onto smaller cells. This enables the use of cells with a high cost per unit area (such as
gallium arsenide) in a cost-effective way. Solar panels also use metal frames consisting of racking
components, brackets, reflector shapes, and troughs to better support the panel structure.
39. DAY 13
• Technologies used in Solar Panels
• Smart Solar Modules
• Maintenance and Mounting of Panels
Most solar modules are currently produced from crystalline silicon (c-Si) solar cells made of multi
crystalline and monocrystalline silicon. In 2013, crystalline silicon accounted for more than 90
percent of worldwide PV production, while the rest of the overall market is made up of thin-film
technologies using cadmium telluride, CIGS and amorphous silicon. Emerging, third generation
solar technologies use advanced thin-film cells. They produce a relatively high-efficiency
conversion for the low cost compared to other solar technologies. Also, high-cost, high-efficiency,
and close-packed rectangular multi-junction (MJ) cells are preferably used in solar panels on
spacecraft, as they offer the highest ratio of generated power per kilogram lifted into space. MJ-
cells are compound semiconductors and made of gallium arsenide (GaAs) and other
semiconductor materials. Another emerging PV technology using MJ-cells is concentrator
Smart solar modules
Several companies have begun embedding electronics into PV modules. This enables performing
maximum power point tracking (MPPT) for each module individually, and the measurement of
performance data for monitoring and fault detection at module level. Some of these solutions
make use of power optimizers, a DC-to-DC converter technology developed to maximize the
power harvest from solar photovoltaic systems. As of about 2010, such electronics can also
compensate for shading effects, wherein a shadow falling across a section of a module causes
the electrical output of one or more strings of cells in the module to fall to zero, but not having
the output of the entire module fall to zero.
Solar panel conversion efficiency, typically in the 20% range, is reduced by dust, grime, pollen,
and other particulates that accumulate on the solar panel. "A dirty solar panel can reduce its
power capabilities by up to 30% in high dust/pollen or desert areas", says Seamus Curran,
associate professor of physics at the University of Houston and director of the Institute for Nano
Energy, which specializes in the design, engineering, and assembly of nanostructures.
40. Paying to have solar panels cleaned is often not a good investment; researchers found panels
that had not been cleaned, or rained on, for 145 days during a summer drought in California, lost
only 7.4% of their efficiency. Overall, for a typical residential solar system of 5 kW, washing panels
halfway through the summer would translate into a mere $20 gain in electricity production until
the summer drought ends—in about 2 ½ months. For larger commercial rooftop systems, the
financial losses are bigger but still rarely enough to warrant the cost of washing the panels. On
average, panels lost a little less than 0.05% of their overall efficiency per day.
Ground-mounted photovoltaic system are usually large, utility-scale solar power plants. Their
solar modules are held in place by racks or frames that are attached to ground-based mounting
supports. Ground based mounting supports include:
• Pole mounts, which are driven directly into the ground or embedded in concrete.
• Foundation mounts, such as concrete slabs or poured footings
• Ballasted footing mounts, such as concrete or steel bases that use weight to secure the
solar module system in position and do not require ground penetration. This type of
mounting system is well suited for sites where excavation is not possible such as capped
landfills and simplifies decommissioning or relocation of solar module systems.
Roof-mounted solar power systems consist of solar modules held in place by racks or frames
attached to roof-based mounting supports. Roof-based mounting supports include:
• Pole mounts, which are attached directly to the roof structure and may use additional
rails for attaching the module racking or frames.
• Ballasted footing mounts, such as concrete or steel bases that use weight to secure the
panel system in position and do not require through penetration. This mounting method
allows for decommissioning or relocation of solar panel systems with no adverse effect
on the roof structure.
All wiring connecting adjacent solar modules to the energy harvesting equipment must be
installed according to local electrical codes and should be run in a conduit appropriate for the
41. DAY 14
• Applications of Solar Energy
• Prime Factors on which Energy Depends
There are many practical applications for the use of solar panels or photovoltaics. It can first be
used in agriculture as a power source for irrigation. In health care solar panels can be used to
refrigerate medical supplies. It can also be used for infrastructure. PV modules are used in
photovoltaic systems and include a large variety of electric devices:
• Photovoltaic power stations
• Rooftop solar PV systems
• Standalone PV systems
• Solar hybrid power systems
• Concentrated photovoltaics
• Solar planes
• Solar-pumped lasers
Solar panel has been a well-known method of generating clean, emission free electricity.
However, it produces only direct current electricity (DC), which is not what normal appliances
use. Solar photovoltaic systems (solar PV systems) are often made of solar PV panels (modules)
and inverter (changing DC to AC). Solar PV panels are mainly made of solar photovoltaic cells,
which has no fundamental difference to the material for making computer chips. The process of
producing solar PV cells (computer chips) is energy intensive and involves highly poisonous and
environmental toxic chemicals. There are few solar PV manufacturing plants around the world
producing PV modules with energy produced from PV. This measure greatly reduces the carbon
footprint during the manufacturing process. Managing the chemicals used in the manufacturing
process is subject to the factories' local laws and regulations.
Variables that affect the amount of solar energy delivered at each part of the
There are two main variables that affect the amount of solar energy delivered at every part of
the world: a) Sun rays inclination at the specific geographical point; and b) Thickness of the
atmosphere between the specific point and the sun.
Figure 1 shows that at a specific point in the globe, there can be two extreme thicknesses of
atmosphere between the sun and the point on the earth’s surface; in one day. At any place
between the two tropics, there are moments where the sun can be at an angle of 90 at noon
(right over our heads), and also at an angle of 0 at sunset. In places off the mentioned earth's
piece of surface, we never have it at 90, but we do have a maximum angle, depending on the
respective latitude. When the sun is at the maximum angle, the energy delivered is highest. This
is because the thickness of the atmosphere is or tends to be d 1 (Figure 1).
42. As the sun moves from a high position to a lower one, little by little, the energy you are receiving,
diminishes until it hides under the horizon.
In Figure 2, you can observe that the rotation axis of the earth, is not perpendicular to the earth's
translation plane around the sun. There is an inclination of a 23.5 angle. The tropics are two
parallel lines around the earth one at the north and the other at the south of the equator.
Gathering the most possible solar energy
Figure shows three graphs that represent the average monthly solar energy delivered in
Monterrey, Mexico, in Kilo-Watt-Hour per square meter. Monterrey is at about latitude 25.6. The
picture shows the monthly average amount of energy delivered every month in a year, in solar
panels at different angles.
Since the sun varies its angle during the day and during the year, there is an angle for every point
in the world, that optimizes the delivered radiation to be captured in the plane of a solar panel.
There are different manners to calculate it, and there are also some simple rules to do it; always
related to the latitude and longitude of the geographical point in the globe. In Figure 9 you'll see
that the further you go to the north, from the equator, the higher the angle of your solar panel
you need in order to optimize energy absorption.
43. Tilt angle - PV array
The tilt angle of the photovoltaic (PV) array is the key to an optimum energy yield. Solar panels
or PV arrays are most efficient, when they are perpendicular to the sun's rays. The default value
is a tilt angle equal to the station's latitude plus 15 degrees in winter, or minus 15 degrees in
summer. This normally maximizes annual energy production.
TILT ANGLE FOR ONGC, DEHRADUN
44. DAY 15
• Introduction to Dynamic Voltage Resistor
CONVENTIONAL DYNAMIC VOLTAGE RESTORER
• Series Injection Transformer
The three single-phase injection transformers are used to inject missing voltage to the system
at the load bus. The working of any series injection transformer depends on the primary
winding voltage, current ratings, the turn-ratio and the short–circuit impedance values.
• Output Filter
In the circuit, there is a need to keep the harmonic voltage that is being generated by the
source voltage to a permissible level i.e. high-frequency harmonics needs to be eliminated,
and this is exactly what output filter does, they are placed either in the line or inverter side.
• Energy Storage Unit
During the compensation, DVR requires real power which can be provided by an energy
storage device. A variety of energy storage technologies are available like flywheel energy
storage, super capacitors, etc. We use DC energy storage device because of its fast response.
• Voltage Source Converter
The VSC is used to either completely replace the supply voltage or to inject the voltage
difference between nominal voltage and the actual one. VSC can also be used in power quality
Fig2. DVR Block diagram
OPERATION MODES OF DVR
• DVR is categorized into three modes of operation that are protection mode, standby mode
and boost mode. In the protection mode, the switches remove the DVR to protect it from
over current that occurs on the load side (the reason for the over current might be the short
circuit of the load). They protect DVR by providing another path for the current to flow. In the
standby mode, DVR can perform any of the two operations depending on the requirement,
either it can go short circuit or it can provide compensation voltage to the compensation
transformer losses. The first operation i.e. short circuit is preferred in steady state because
45. the loss in voltage is very small which does not disturb the requirement of load, but the only
necessary condition for this assumption to be true is “that the circuit should not be weak.” In
boost or injection mode, the DVR injects the voltage with the help of voltage injection
transformer after the detection of any disturbance in the supply voltage.
Fig 3. Protection Mode
Fig 4. Stand-by Mode
COMPENSATION STRATEGIES IN DVR
Three different ways of compensation are possible pre –fault, post-fault and zero energy
• Post-fault Method
In the post-fault mode, the voltage that is to be injected is in phase with the source voltage,
whereas the amplitude of the load voltage is kept constant. This technique requires smallest
amount of injection voltage and largest amount of active power. To perform post-fault
compensation, the measurement determines the depth of the voltage sag and the phase
angle of voltage(source). On the basis of the measured data, the system will generate a
reference sinusoidal signal of equal magnitude and phase angle of that of measured data.
After that, the signal is fed to the inverter to generate compensation voltage and then it is
added to the source voltage to restore the load voltage.
46. Fig 5a. Phasor Diagram of Post-Sag Mitigation
• Pre- fault Method
Pre-fault mode or phase jump mode is employed to protect the loads from phase-jump.
Basically, in post-fault method, only the magnitude is restored but the phase remains
defected so for the devices which might produce faulty results because of disadvantage we
prefer pre-fault method. As it is clear it restores both magnitude and phase angle (prior to
voltage sag) of load voltage, here the injection voltage is either greater than or equal to
voltage injected in case post-fault method.
Fig 5b. Phasor Diagram of Pre-Sag Mitigation
• Zero Energy Compensation Method
In zero energy compensation, the compensation voltage is injected orthogonal to that of load
current (after compensation), therefore there is no transfer of active power between the load
and the DRV. Since the requirement of active power is zero, there is no need of any sources
of energy like battery in DRV. The method above is employed for the high-power load
protection. The unit employed for the estimation in DRV continuously monitor the source
voltage of the industrial plant, as soon as a drop of 10% or more is detected, a reference
signal is calculated using the measured data with the help of compensation unit. The Voltage
across DC link capacitor will remain same during compensation. The Output voltage can be
47. DAY 16
• Implementation of Multilevel Inverter in DVR
Now a day’s many industrial applications have begun to require high power. Some appliances in
the industries, however, require medium or low power for their operation. Using a high-power
source for all industrial loads may prove beneficial to some motors requiring high power, while
it may damage the other loads. The multi-level inverter has been introduced as alternative in
high power and medium voltage situations. Multilevel inverters are source of high power, often
used in industrial applications and can use either sine or modified sine waves. Instead of using
one converter to convert an AC current into a DC current, a multilevel inverter uses a series of
semiconductor power converters (usually two to three) thus generating higher voltage.
A desired output voltage waveform can be synthesized from the multiple voltage levels with less
distortion, less switching frequency, higher efficiency, and lower voltage devices. Multilevel
inverters are of three types.
• Diode clamped multilevel inverter
• Flying capacitors multilevel inverter
• Cascaded H- bridge multilevel inverter
A generalized multilevel topology can be given as
All the existing multilevel inverters can be derived from this topology. Moreover, this topology
provides a true multilevel structure that can balance each dc voltage level automatically at any
number of levels regardless of active or reactive power conversion without any assistance from
other circuits. The operating principle of this circuit can be given as:
Switches Sp1–Sp4 and Sn1–Sn4 and in bold lines are the main devices to produce desired voltage
waveforms. The rest of the switches and diodes are for clamping and balancing the capacitors’
48. voltages, i.e., voltage levels. On-state devices diodes Dp1–Dp4 are necessary to produce the
desired voltage level. The switches Sc1, Sc5, and Sc11 are gated on so that the capacitors C1, C3,
C6, and C10 are connected in parallel to balance their charges (i.e. VC1=VC3=VC6=VC10). Similarly,
the switches Sc3 and Sc9 are gated on so that the capacitors C2, C5, and C9 are charge-balanced
(i.e. VC2=VC5=VC9). And Sc7 is gated on letting C4 and C8 be charge-balanced (i.e. VC4=VC8). In this
way, all capacitors’ voltage can be balanced and the output waveform can be produced.
ADVANTAGES OF MULTI-INVERTER
• Bridges can be controlled independently irrespective of the number of bridges which
permits compensation of single phase voltage.
• Due to the same structure, the packing and the modularization of the circuit is possible and
it also allows removal of transformer connected in series which decrease the size and cost
• The H-bridge require larger capacitor’s in its circuit due to second harmonics this might
sound like a drawback but as the capacitance increases the energy storing capability also
increases. which if used might turn the disadvantage into advantage.
• The multilevel inverters produce common mode voltage, reducing the stress on the motor
and preventing any serious damage.
FEEDBACK CONTROLLER IN MUTI-LEVEL INVERTER
The feedback controller used in this application either utilizes the PI algorithm or the fuzzy
• Proportional Integral Controller
PI control is required for non-integrating processes, in simple words any process that eventually
returns to the same output when the same set of inputs and disturbances are given. For
integrating processes, a P-only controller is best suited. The integral action of a controller is used
to remove offset and can be thought of as an adjustable Vbias.
PID algorithm is described by:
where y is the measured process variable, u is the control signal, r the reference variable and e is
the control error (e = ysp − y). The reference variable is often called the set point. The control
signal is a sum of three terms: The P-term (proportional to the error), the I-term (proportional to
the integral of the error), and the D-term (proportional to the derivative of the error). The
controller parameters are proportional gain K, integral time Ti, and derivative time Td.
• Fuzzy Logic Controller
Fuzzy logic (FL) controller is the heart of fuzzy set theory. It uses linguistic variables rather than
numerical variables. The technique relies on human capability to understand the behaviour of
the system and is based on the quality control rules. It(Fuzzy logic) provides a simple way to arrive
at a conclusion based upon missing input information, vague, noisy or ambiguous.
49. DAY 17
• Ways to improve efficiency of solar panels
Improving Solar Cell Efficiency:
Improved antireflective coatings, textures, and other materials
• Have you ever looked at a solar panel and seen that one of the solar cells is slightly off
color? The consistency of the color of a solar cell is one indication of its quality and its
ability to produce power. Developing more consistent manufacturing processes can be a
relatively easy way to improve panel efficiency.
Reduce the shading caused by the busbars
• When you look at the front of the solar panel at the cells, there may be silvery lines across
them going horizontally or vertically. These are tiny metal wires on the front of the solar
cells, called “busbars,” and they help the electricity which is generated flow out of the cell
into your home.
• However, they do cause some of the light to be reflected, rather than be converted into
energy. Manufacturers have been working to make the wires thinner, or even eliminate
them altogether. The highest-efficiency premium plus panels have “rear contacts” where
all the wires are on the back and the entire front of the cell is a single color.
Use both sides of the solar cell
• Most solar panels use a standard white or black “backsheet” which provides a sturdy
backing layer to attach the solar cells. But some panels are clear on both sides, and can
absorb light from either side. This technology has sometimes been called “Bifacial” meaning
both sides of the solar cell can absorb light.
• Pack cells in more tightly on the panel
• Those white spaces you see between cells and along the edge are wasted solar panel area.
In addition, the corners of the cells themselves are cut off, leaving even more space.
Manufacturers are finding ways to eliminate the gaps or even overlap the cells and produce
High-efficiency technologies here or coming down the road
Technology improvements will increase the efficiency of all types of solar panels, and the
performance improvements will be seen through all of EnergySage’s classifications.