ELECTROTREND ISSUE 1

ELECTROTREND

ISSUE 1 2017

Department of Electrical Engineering
VIVA Institute of Technology

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Disclaimer

ELECTROTREND: A annual Technology Review Magazine Is Published by the Electrical
Engineering Department OF VIVA Institute Of Technology. Views and opinions expressed in the
ELECTROTREND are those of individual authors and contributors and it not in any way is reflection
of official views or policy of the editors of publishers. This should not be construed as legal or
professional advice. The publishers, editors and contributors are not responsible for any decision taken
by the readers on the basis of these views and opinions.
Although every case is taken to ensure genuineness of the writing in the publication, the publisher
Electrical Engineering Department VIVA Institute Of Technology, does not attest to the originality of
the respective authors content.
Instructors are permitted to photocopy the articles of non-commercial purpose with proper
acknowledgement of the authors.
© 2017, Electrical Engineering Department, VIVA Institute of Technology, All rights reserved.
Principal: Dr. Arun Kumar.
HOD: Prof. Bhushan Save.
Editor: Prof. Vinayak Gaikwad.

Prof. Piyali Mondal.
Published by: Electrical Engineering Department, VIVA Institute of Technology

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THE PRINCIPAL DESK

Dear readers,

It is a matter of immense pleasure to know that Electrical Engineering department has taken keen
interest to create a common platform for the faculty and students to go beyond the class room
activities, to explore new possibilities and collaborate with technology dynamically.
I am confident that this magazine will give impetus to research culture amongst students and faculty
with emphasis on entrepreneurship.
I congratulate the entire editorial team for their hard work and dedication in giving requisite shape to
this magazine.
I hope this magazine will inspire passion among the faculty and students.
I wish them all the very best for their future endeavors as well.
DR. ARUN KUMAR
PRINCIPAL
VIVA INSTITUTE OF TECHNOLOGY

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FROM HOD’S DESK

Dear Readers,

Learning is a continuous process. Throughout life a human being remains student. Based on

the same, Department of Electrical Engineering of VIVA Institute Of Technology is glad to present in
front of you a new technical magazine “ELECTROTREND”. In this we encourage our students and
faculty members to present articles on new technologies in engineering going on all across the world.

Now days the technology changes with rapid speed; due to which it‟s impossible for anyone to
survive with his existing knowledge for long term without upgrading to recent trends. It seems to be
very important to be in touch with recent trends in engineering. To achieve this effectively faculty
members and students needs to be motivated to read and write article based on new technology in
engineering. “ELECTROTREND” is platform provided by department of Electrical Engineering to
explore hidden talent is faculty and students.

The department of electrical engineering also focuses on high level of teaching quality during
lectures and practices. We also encourage students to participate in workshops, conferences, STTP and
technical competition. “ELECTROTREND” will help student to grow in all aspects of electrical
engineering such as Power system Analysis & Protection, Renewable Energy & its sustainability,
Smart grid Technology, Advance trends in Electrical engineering and so on. At last I wish to
congratulate all members who have participated for making this magazine successful.

PROF. BHUSHAN SAVE
HEAD OF DEPARTMENT
DEPARTMENT OF ELECTRICAL ENGINEERING

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Vision of the Institute

Viva Institute of Technology strives to impart total quality education by means of equip
students with knowledge and skills in their chosen stream, inculcate cultural and ethical
values, identify hidden talents, provide opportunities for students to realize their full
potential and thus shape them into future leaders, entrepreneurs and above all good human
beings.

Mission of the Institute

To develop the standard of the institute above bench mark level, providing students with
advanced knowledge and latest technology in the chosen discipline by tapping their hidden
and obvious potential, molding them into good and responsible citizens by playing a
meaningful role in industry and society

Department Vision

The vision of Electrical Department is to build up a research identity in all areas of Electrical
Engineering uniquely. Through core research and education the students will be prepared as
the best professional engineers in the field of Electrical Engineering to face the challenges in
such disciplines.

Department Mission

The Electrical Engineering Department imparts high quality teaching, research and services
that provide students a supportive environment. The department makes the best effort to
promote intellectual, ethical and technological environment to the students. The department
invokes the desire and ability of lifelong learning in the students for pursuing successful
career in engineering.

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Contents

Sr No Article Page No

1 TANDEM CELLS 7

2 IMPORTANCE OF ELECTRICAL MACHINE 10

MAINTENANCE

3 CULTIVATING RURAL TECHNOLOGY FOR 13

DEVELOPMENT

4 DYNAMIC VOLTAGE RESTORER TO MITIGATE 16

VOLTAGE SAG AND SWELL

5 ELECTRICITY GENERATION FROM BIOWASTE 18

BASED MICROBIAL FUEL CELLS

6 RENEWABLE ENERGY SCENARIO IN INDIA 20

7 RECENT UPDATES ON BIOGAS PRODUCTION 24

8 CASE-STUDY-OPTIMIZATION AND MODELING 28

OF HYBRID SYSTEM FOR TUMNIPADA

VILLAGE WITH REAL TIME DATA

9 HOW TO SAFELY MANAGE SINGLE-CELL 30

BATTERIES FOR PORTABLE DEVICES

10 ELECTROPORATION 33

11 LITHIUM-ION BATTERY 36

12 HUMAN MACHINE INTERFACE 38

13 WIRELESS POWER TRANSMISSION 41

14 HIGH POWER SUPER CAPACITORS FROM 44

CARBON NANOTUBES

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TANDEM CELLS

Tandem cells or Multi-junction (MJ) solar cells are solar cells with multiple p–n

junctions made of different semiconductor materials. Each material's p-n junction will produce current
in response to various wavelengths of light. The use of multiple semiconducting materials allows the
absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy
conversion efficiency.
Solar power in India is a fast-growing industry and as of 30 Sept. 2016, the country's solar grid had a
cumulative capacity of 8,626 megawatts (MW) or 8.63 gigawatts (GW). In January 2015, the
government of India expanded its solar plans, targeting US$100 billion of investment & 100 GW of
solar capacity, including 40 GW's directly from rooftop solar, by 2022. The tremendous growth in
deployment of solar power is recorded and updated monthly on the Government's Ministry of New
and Renewable Energy website. Large scale solar power deployment began only as recently as 2010,
yet the aspiring targets would see India installing more than 2 times that achieved by world
leaders China or Germany in all of the period up to 2015 year end. A solar cell, or photovoltaic
cell previously named solar battery. By photovoltaic effect, it transforms energy of light into
electricity which is a physical & chemical phenomenon. It is a form of photoelectric cell, defined as a
device whose electrical characteristics, such as voltage, current or resistance, vary when disclosed to
light. Solar cells are the foundation of photovoltaic modules, otherwise known as solar panels.

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Traditional single-junction cells have a maximum theoretical efficiency of 34%. Theoretically, an
infinite number of junctions would have a limiting efficiency of 86.8% in the case of highly
concentrated sunlight. Currently, the best lab examples of traditional crystalline silicon solar cells have
efficiencies between 20% and 25%, while lab examples of multi-junction cells have shown performance
over 46% under concentrated sunlight. Commercial examples of tandem cells are widely available at
30% under one-sun illumination, and improve to around 40% incase of concentrated sunlight. However,
this efficiency is gained at the cost of increased complexity and manufacturing price. To date, their
higher price and higher price-to-performance ratio have restricted their use to special roles, notably in
aerospace where their high power-to-weight ratio is desirable. In terrestrial applications, the above
mentioned solar cells are emerging in concentrator photovoltaics (CPV), with an increasing number of
installations around the world

Tandem fabrication techniques have been used to improve the performance of existing designs.
Specifically, this technique can be applied to reduce cost thin-film solar cells using amorphous silicon,
as opposed to conventional crystalline silicon, to produce a cell with around 10% efficiency that is low
in weight and flexible. This approach has been used by many commercial vendors, but these products
are currently limited to certain niche roles, like roofing materials.Cells made from multiple materials
have multiple bandgaps. So, it will respond to multiple light wavelengths and some of the energy that
would otherwise be lost to relaxation as mentioned above, can be captured and converted. For instance,
if one had a cell with two bandgaps in it, one tuned to red light and the other to green, then the extra
energy in green, cyan & blue light would be lost only to the bandgap of the green-sensitive material,
while the energy of the red, yellow and orange would be lost only to the bandgap of the red-sensitive
material. Following analysis in a similar manner to those performed for single-bandgap devices, it can
be demonstrated that the perfect bandgaps for a 2-gap device are at 1.1 eV & 1.8 eV.
Conveniently, light of a particular wavelength interact weakly with materials that are of bigger
wavelength. This means that you can make a multi-junction cell by layering the various materials above
each other, shortest wavelengths on the “TOP” and increasing through the body of the cell. As the
photons have to pass through the cell to reach the proper layer to be absorbed, transparent conductors
are needed to collect the electrons being generated at each layer. The structure of an MJ solar cell.
There are six important types of layers: back surface field (BSF) layers, pn junctions, window layers,
tunnel junctions, anti-reflective coating and metallic contacts.

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Manufacturing a tandem cell is not an easy task, largely due to the thinness of the materials and the
difficulties extracting the current between the layers. The easy solution is to use 2 mechanically
separate thin film solar cells and then wire them together separately outside the cell. This technique is
widely used by amorphous silicon solar cells; Uni-Solar's products use 3 such layers to reach
efficiencies around 9%. Lab examples using more exotic thin-film materials have demonstrated
efficiencies over 30%.
The difficult way is the MONOLITHICALLY INTEGRATED cell, these are electrically and
mechanically connected & the cell consists of a number of layers. These cells are much more difficult
to produce because the electrical characteristics of every layer have to be carefully matched. In
particular, the photocurrent generated in every layer needs to be matched; otherwise electrons will be
absorbed between layers. This limits their construction to certain materials, best met by the III-V
semiconductors.

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PrPofr.oAf.dAildSilhSeihkehikh

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IMPORTANCE OF ELECTRICAL MACHINE
MAINTENANCE

In a company machine operator is given responsibility of machine. He is very excited to

impress his senior. It might be that the company will progress fast and he will get fast promotion. So
the production is more and he never shutdown the machine for even one day. Machine operating
continuously, results in higher production, But after some time due to lack of maintenance production
capability of the machine decreases. Therefore, there must be a balance between P (production) and
PC (production capability). If he would have given attention to maintain the motor in proper
condition then machine‟s production capability would have remains maintained. Also failure rate of
machine would have been decreases.

Maintenance of Electrical Machine
Induction motors are the main workhorse of industrial prime movers due to their ruggedness, low cost,
low maintenance, reasonably small size, reasonably high efficiency, and operating with an easily
available power supply. About 50 % of the total generated power of a nation is consumed by these
induction motors. This statistics gives an idea regarding the use of huge number of induction motors,
but they have some limitations in their operating conditions. If these conditions exceed then some
premature failure may occur in stator or/and rotor. This failure, in many applications in industry, may
shut down, even, the entire industrial process resulting loss of production time and money. Hence, it is
an important issue to avoid any kind of failure of induction motor. Operators and technicians of
induction motors are under continual pressure to prevent unscheduled downtime and also to reduce
maintenance cost of motors. Maintenance of electrical motors can be done in three forms: breakdown
maintenance, fixed-time maintenance, and condition-based maintenance.

In breakdown maintenance, the strategy is „run the motor until it fails‟ which means maintenance
action is taken only when the motor gets break down. In this case though the motor may run
comparatively for a long time before the maintenance is done but when break down occurs it is
necessary to replace the entire machine which is much costlier compared to replacing or repairing the
faulty parts of the motor. Also it causes loss of productivity due to downtime.

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In fixed-time maintenance, motor is required to stop for inspection which causes long downtime. It
also causes loss of productivity due to downtime. Also trained and experienced technical persons are
required to recognize each and every fault correctly. All these necessitate the condition-based
maintenance of the motor. In this form of maintenance, motor is allowed to run normally and action is
taken at the very first sign of an incipient fault. There are a number of works on this online condition
monitoring of induction motor.

In condition monitoring, when a fault has been identified, sufficient data is required for the plant
operator for the best possible decision making on the correct course of action. If data is insufficient
there remains the chance for wrong diagnosis of fault which leads to inappropriate replacement of
components, and if the root of the problem is not identified properly, the replacement or any other
action taken already will succumb to the same fate. In condition monitoring, signals from the
concerned motor are continuously fed to the data acquisition system and the health of the motor is
continuously evaluated during its operation for which it is also referred as online condition monitoring
of motor, and hence it is possible to identify the faults even while they are developing. The
operator/technician can take preparation for the preventive maintenance and can arrange for necessary
spare parts, in advance, for repairing. Thus condition monitoring can optimize maintenance schedule
and minimize motors downtime and thereby increase the reliability of the motor.

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Advantages of using condition monitoring
The advantages are mentioned as below:

• Can predict the motor failure.
• Can optimize the maintenance of the motor.
• Can reduce the maintenance cost.
• Can reduce downtime of the machine.
• Can improve the reliability of the motor.

By,
Prof. Anoj Kumar Yadav

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CULTIVATING RURAL TECHNOLOGY FOR
DEVELOPMENT

Simple ideas make lofty technology. Rural traditions of life and workmanship need a

scientific revamp still maintaining its rural identity. The second annual event of India International
Science Festival (IISF) this year towed along several such instances of profound ideas. Drinking water
often remains contaminated with microbes and particles. Who has thought of making a earthen pot
subjected to a compression that minimizes its pores that let in contamination? A simple strategy with
profound effect costing barely 350 to 450 Rs. A baked clay technology for microbial filtration as well
as for turbidity removal in drinking water at point-of use was on display at the Unnat Bharat Abhyan
pavilion at IISF 2016.

The contaminated drinking water is filled in the frustum (upper-half of inverted cone) shaped filtering
container made of baked salty clay, having micro- pores of nano size through which water percolates
due to gravity. An average of 8 liters percolates in 10 hours. The percolated water filtrate remains free
from contaminants of sizes larger than 10-6m to 10-9m. „The microbial test of E.Coli strains of
MC4100 and W3110 showed 99.99% removal efficiency conforming to the required standards of
drinking water set by the World Health Organization. Approximately 90% reduction in turbidity and
50% reduction of total dissolved salts and electrical conductivity is also achieved.‟ It has been tested
by National Test House, Jaipur. Clay pots compatible for microwave ovens is an intriguing thing. Dr
Lalithambika is a retired scientist from CSIR with expertise in Clay Science and Technology. „Clay
has a lot of metal presence, mostly iron and lead. We use density separation and particle separation to
get rid of their presence. And then the baked pot can withstand heating in a microwave oven.‟ explains
Dr Lalithambika about her heat-resistant pots.

“We are providing training to potters on how to apply France‟s „decoupage‟ technique to decorate
finished products, mainly those in terracotta category. Customer-specific decorations can be made on
clay products using the technique. ” informs Dr Lalithambika who has been working with potters for
over three decades. “We have already trained over 200 potters in Palakkad and they all feel that the
value addition is beneficial. It helps them regain lost markets,” she says. The state of Kerala has a
sizeable potter population of over 650 colonies who were practicing traditional methods impinging

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upon efficacious production. The Department of Science and Technology of Government of India has
been sponsoring the core support program of, „revamping of traditional pottery‟. Integrated Rural
Technology Centre (IRTC) under the Kerala Sasthra Sahitya Parishad (KSSP) has launched a major
value-addition initiative by blending traditional Kerala pottery with French aesthetics, to ensure
livelihood security for potters sponsored by Khadi and Village Industries Commission of Government
of India. The value-added products are helping the potters find newer markets and earn better revenue.
IRTC is also sending the products to retail networks in Delhi, Mumbai, and other major cities. The
Department of Science and Technology of Government of India has also been sponsoring the initiative
of, „value-addition of terracotta materials by modernization of techniques and introduction of
innovative products‟ and also the initiative of, „decorative pottery as an income generating activity for
the weaker sections of the society‟.

In the hilly regions above 6000 feet in the Himalayas, domestic fuel wood consumption tantamount to
10 metric tons per household of 5 to 6 members. 70% of this fuel is used up solely for heating house
space and water. Dr. Lal Singh surveyed this fact in Himachal Pradesh while running his NGO called
Himalayan Research Group, a core group under the Department of Science & Technology of
Government of India. According to him, solar water and space heating collectively mitigates around 5
metric tons of carbon emission per household per annum. Besides, indoor pollution is cut down and
there is remarkable amount of forest conservation.
„These areas have sunny days for most of the period in a year. We went on to install 200 solar water
heating panel and 100 space heating panels in Shimla, Manali and Kullu districts of Himachal
Pradesh. Now installing of 160 such panels is underway in remote and tribal valley of Zanskar in

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Jammu & Kashmir under DST-TIME-LEARN programme‟, declares Dr Lal Singh. About the
efficiency he says, „Solar water heating panel achieves 900 C water temperature in full sun initially in
35-45 minutes and successively in 20-25 minutes. It can provide 100-200 litres of water per day on
sunny days. Space heating panel blows air maximum at 650C and improve 100-150 C temperature of
living space inside house and some warmth remains far beyond sunset lasting up to 10 pm. The entire
installation can be made by a local carpenter and its cost hovers around Rs. 35,000 and after subsidy it
comes down to below Rs. 20,000.

By,
Prof. Harshal Gosavi.

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DYNAMIC VOLTAGE RESTORER TO MITIGATE
VOLTAGE SAG AND SWELL

Dynamic Voltage Restorer (DVR) is a series voltage injection device. It is used to improve

the power quality condition in the transmission as well as in distribution line. DVR is basically a
power electronic device comprising of an inverter, energy storage device and a LC filter at the output
of inverter. This basic structure may have coupling transformer to couple it with transmission or
distribution line. In a transmission line, it is used to improve maximum transmissible power, voltage
stability, and transient stability and damp the power oscillations. In distribution system it is used to
mitigate sag and also used as an active filter for harmonic compensation.

Series capacitive compensation reduces the line inductance and thereby increases the line current.
This can be seen by in another way. To increase the line current, voltage across the line impedance
must be increased. Capacitor also does the same thing as voltage across the capacitor is in opposition
to the voltage drop in the line impedance. So the physical nature of series circuit element is irrelevant
as long as it produces the desired compensating voltage. Thus an alternate compensating circuit may
be envisioned as an AC voltage source which directly injects the desired compensating voltage in
series with the line. This injected ac voltage can be controlled as per the required compensation level.

Voltage source inverter (VSI) can be used to generate the ac voltage at desired frequency with
controllable amplitude and phase angle. This generated voltage can‟t be directly fed into the line as
inverter output voltage has switching harmonics. DVR is the combination of VSI and filter. DVR is
primarily used to mitigate the sag swell problems in receiving end voltage. In a transmission system, it
can be used to improve the voltage stability, transient stability and to damp the power oscillations.

DVR is connected in series with the distribution feeder-2 that supplies a sensitive load. For a
fault clearing or switching at point A of the incoming feeder or fault in the distribution feeder-1, the
voltage at feeder-2 will sag. Without the presence of the DVR, this will trip the sensitive load causing
a loss of production. The DVR can protect the sensitive load by inserting voltages of controllable

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amplitude, phase angle and frequency (fundamental and harmonic) into the distribution feeder via a
series insertion transformer. It is however to be mentioned that the rating of a DVR is not unlimited.

The charge less device control using cell phone is designed using ring counts. The ring is connected
by using ring detector circuit. The IC 4017 based ring detector circuit gives sequence pulses to
capacitor charger based comparator circuit. Where capacitor provide input values for each comparator.
For each ring any one of the comparator is selector and capacitor starts to charge. The 1K and 10K
based voltage divider circuit provide reference values for each comparator. In our demo version we
choose rings 3, 5 and 7 for operating the electrical device. After making required ring the
corresponding RC network charger and produce pulses to next stages. In microcontroller, toggle
operation is carried on.

By,
Prof. Kavita Mhaskar.

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EELLEECCTTRRIICCIITTYY GGEENNEERRAATTIIOONN FFRROOMM
BIOBWIOAWSTAESBTAESBEADSEMDICMRIOCBRIOABLIAFULEFLUCELELLS

CELLS

In this article, it has been established that voltage generated in a microbial fuel cell decreases

linearly with respect to time. In other words, the first order derivative of voltage generated with
respect to time is a negative constant. Thus the rate of change of voltage generated with respect to
time has been established to be independent of time. It has been found that a mixture of bio wastes can
actually result in higher extractable current than any single component although this is not always true
in general. Further, it has been found that when a component results in higher voltage production, it
ends up reducing the cell life.

A salt solution, in our case, of pure NaCl, would be added to each of the bio-waste samples to make
the mixture electrically conductive. This mixture would be placed in a sealed chamber to stop entering
of oxygen, thus forcing the microorganism to use anaerobic respiration. An electrode would then be
placed in the solution that would act as the anode. In the second chamber of the MFC there would be
placed another solution and another electrode. This electrode, called the cathode would be positively
charged and would be the equivalent of the oxygen sink at the end of the electron transport chain, only
now it would be external to the biological cell. The solution would be an oxidizing agent that would
pick up the electrons at the cathode. In our case, we shall use potassium ferricyanide as the oxidizing
agent. Potassium ferricyanide is added to the cathode to accept electrons. It is very reactive with the
graphite electrode. Ferricyanide has a fairly positive potential compared to the organic matter in the
anode and helps to drive the flow of electrons. With the addition of ferricyanide ions, the power can be
increased 50-80% over a MFC with dissolved oxygen.

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An MFC with Drain water and Slurry Connecting the two electrodes would be a wire and completing
the circuit and connecting the two chambers there would be a salt bridge. In place of commercially
available electrodes, graphite rods extracted from dry cells would be utilized, the tips of which had
been soldered to copper wires traveling from one chamber to the other. The soldering was performed
at a melting temperature of 391o C. For preparation of salt bridges, a water solution containing
concentrations of 3% NaCl and 1.6% agar was allowed to boil inside a microwave oven for nearly 3
minutes. The hot solution was poured into sawed PVC pipe sections each of length 4 inches by sealing
one end with polythene. The setup was thereafter allowed to cool for nearly 2 hours inside a High
Efficiency Performance Air Filter. The salt bridges were thus ready for use.

By,
Prof. Mukesh Mishra.

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RENEWABLE ENERGY SCENARIO IN INDIA

Energy is one of the major inputs for the economic development of any country. In the case

of the developing countries, the energy sector assumes a critical importance in view of the ever
increasing energy needs requiring huge investments to meet them. Renewable energy is energy
obtained from sources that are essentially inexhaustible. Examples of renewable resources include
wind power, solar power, geothermal energy, tidal power and hydroelectric power. The most
important feature of renewable energy is that it can be harnessed without the release of harmful
pollutants. Non-renewable energy is the conventional fossil fuels such as coal, oil and gas, which are
likely to deplete with time.

Present Power Scenario of India
Almost all the States in India are facing energy shortages in the range of 3% to 21% with national
average energy shortage of about 10.3% and shortage in peak demand is 15.4%. RES can supplement
the present supply-demand gap and at the same time, can address the environmental and energy
security issues. Renewable energy technologies have a good potential in India and considerable
progress has been achieved so far. Substantial efforts at government, public and private levels have
been made to harness the non-conventional and renewable sources of energy during the last three
decades.

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The MNRE efforts have been identified in following four areas:
Power generation from renewable
• Grid-interactive renewable power (Wind Power, Small Hydro Power (SHP), Biomass Power, Urban
& Industrial Waste-to-energy and Solar Power),
• Captive/CHP/Distributed Renewable Power (such as Biomass/Cogeneration, Biomass Gasifier,
Waste-to energy, Aero-generator/Hybrid Systems)
Rural & Decentralized Energy System (such as Family type Biogas Plants, Home Lighting System,
Solar Photovoltaic (SPV)/Thermal Program, Wind Pumps)
Remote Village Electrification
Other programs (such as Energy Parks, Akshay Urja Shops and Hybrid Vehicles)

Renewable energy sources such as wind, solar, biomass and SHP are getting greater recognition in
meeting the day-to-day energy requirements for captive power of domestic, commercial and industrial
sectors.
Incentives & Promotion Policies
The MNRE has been providing capital subsidy as Central Financial Assistance (CFA), which varies
according to the type and the size of the plants and the category of institutions and areas to promote
RES (grid-interactive). Besides the CFA, fiscal incentives such as 80% accelerated depreciation,
concessional import duty, excise duty, tax holiday for several years, etc., are available for RES.

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Specialized Centers/Institutes
MNRE also established and developed several specialized centers to play a major role in providing
technical, R&D and financial back-up for promoting renewable energy programs, such as:
(1) Centre of Wind Energy Technology (CWET), established in 1982
(2) Solar Energy Centre (SEC),
(3) Alternate Hydro Energy Centre (AHEC) established in 1982,
(4) Sardar Swaran Singh - National Institute of Renewable Energy (SSS-NIRE)
(5) Indian Renewable Energy Development Agency Limited (IREDA) established in 1987.
India has huge potential for producing power from Renewable Energy Sources (RES). Over the last
few decades, in particular, Government of India has endeavored to lay the foundation for a broad-
based renewable energy program and designed it specially to meet the growing energy needs, and to
fulfill energy shortage and security concerns of the country. Considerable experience and capabilities
exist in the country on renewable technologies. Although at present the contribution of renewable
energy is small, but future developments might make RES technology more competitive to displace
conventional energy sources. Prospects for RES are steadily improving in India towards a great future.
It is destined to take a leading role in the global renewable energy movement aiming towards
sustainable development. The strategy for achieving these enhanced goals will mainly depend on the
active participation of all players i.e. from government agencies to NGO‟s, from manufactures to
R&D institutions, from financial institution to developers and of course a new breed of energy
entrepreneurs.

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By,
Prof. Piyali Mondal

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RECENT UPDATES ON BIOGAS PRODUCTION

One of the greatest challenges facing the societies now and in the future is the reduction of

greenhouse gas emissions and thus preventing the climate change. It is therefore important to replace
fossil fuels with renewable sources, such as biogas. Biogas can be produced from various organic
waste streams or as a byproduct from industrial processes. Beside energy production, the degradation
of organic waste through anaerobic digestion offers other advantages, such as the prevention of odor
release and the decrease of pathogens. Moreover, the nutrient rich digested residues can be utilized as
fertilizer for recycling the nutrients back to the fields. However, the amount of organic materials
currently available for biogas production is limited and new substrates as well as new effective
technologies are therefore needed to facilitate the growth of the biogas industry all over the world.
Hence, major developments have been made during the last decades regarding the utilization of
lignocellulosic biomass, the development of high rate systems, and the application of membrane
technologies within the anaerobic digestion process in order to overcome the shortcomings
encountered. The degradation of organic material requires a synchronized action of different groups of
microorganisms with different metabolic capacities. Recent developments in molecular biology
techniques have provided the research community with a valuable tool for improved understanding of
this complex microbiological system, which in turn could help optimize and control the process in an
effective way in the future.
Biogas production through anaerobic digestion (AD) is an environmental friendly process utilizing the
increasing amounts of organic waste produced worldwide. A wide range of waste streams, including
industrial and municipal waste waters, agricultural, municipal, and food industrial wastes, as well as
plant residues, can be treated with this technology. It offers significant advantages over many other
waste treatment processes. The main product of this treatment, i.e., the biogas, is a renewable energy
resource, while the by-product, i.e., the digester residue, can be utilized as fertilizer because of its high
nutrient content available to plants. The performance of the AD process is highly dependent on the
characteristics of feedstock as well as on the activity of the microorganisms involved in different
degradation steps. The conversion of organic matters into biogas can be divided in three stages:
hydrolysis, acid formation, and methane production. In these different stages which are however

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carried out in parallel, different groups of bacteria collaborate by forming an anaerobic food chain
where the products of one group will be the substrates of another group. The process proceeds
efficiently if the degradation rates of the different stages are in balance.
There is an increasing interest in bioenergy production across the world for environmental as well as
economic and social reasons. The production of biogas contributes to the production of renewable and
sustainable energy since biogas works as a flexible and predictable alternative for fossil fuels. The
main political driving forces linked to the biogas system have a country specific variation. Within the
European Union, well-developed biogas industry can be found in Germany, Denmark, Austria, and
Sweden followed by the Netherlands, France, Spain, Italy, the United Kingdom, and Belgium. In these
countries, with a strong agro-sector, reduction of nutrient emissions and renewable energy production
are equally strong driving forces supporting biogas production. In other countries, like Portugal,
Greece, and Ireland, as well as in many of the new East-European member states, the biogas sector is
currently under development, due to the identified large potential for biomass utilization there. The
biogas plants in Europe are classified based on the type of digested substrates, the technology applied,
or the size of the plant. In this sense, they are usually considered as large scale, joint co-digestion
plants or farm scale plants. Nevertheless, there are no major differences between these two categories
regarding the technology used. Simultaneous digestion of a mixture of two or more substrates is called
co-digestion. The coexistence of different types of residues in the same geographic area enables
integrated management, offering considerable environmental benefits, like energy savings, recycling
of nutrients back to the agricultural land, and reduction of CO2 emissions. Due to the different
characteristics of waste streams treated together, co-digestion may enhance the performance of the AD
process owing to a positive synergism established in the digestion medium by providing a balanced
nutrient supply and sometimes by suitably increasing the moisture content required in the digester.
Joint biogas plants are referred to large scale plants, with digester capacities ranging from few
hundreds m3 up to several thousands m3.

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Different organic waste streams are collected and transported to the plant and co-digested there. The
process is running either at thermophilic or mesophilic conditions, using hydraulic retention times
(HRT) of 12–25 d. HRT is normally inversely proportional to the process temperature. Generally, the
substrates and in particular animal by-products, which are to be sent to the digester, first go through a
controlled pre-sanitation phase, to inactivate pathogens and to break their propagation cycles. After
the AD process, the digested residue is transferred to storage tanks, which are typically covered with a
gas proof membrane for the recovery of the remaining gas and to prevent methane leakage to the
atmosphere. The digested residue has a high nutrient content, and therefore, it can be recycled to the
fields as fertilizer. The produced biogas is utilized as a renewable energy source. In Europe, biogas is
mainly used for generating heat and electricity. Some of the produced heat is utilized within the biogas
plant as process heating and the remaining heat is distributed through districts` heating systems to
consumers. The produced power is sold to the grid. In some countries, like Sweden, the produced
biogas is upgraded to bio-methane which is utilized as vehicle fuel. Above figure shows the biogas
production cycle within an integrated system. Recently, co-digestion has taken much attention since it
is one of the interesting ways of improving the yield of AD. Most of the investigations on co-digestion
were carried out in batch operation mode and many researchers have pointed out the influence of
synergy, due to a balanced mixture composition, on methane yield reported that it was possible to
relate synergetic effects with up to 43% enhancement in methane yield (YCH4) compared with the
expected YCH4 calculated on basis of methane potentials obtained for the individual substrates. The

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substrates investigated were four different waste streams, such as slaughterhouse waste, various crop
residues, manure, and the organic fractions of municipal solid waste (OMSW). A successful co-
digestion is not simply a digestion of several waste streams treated at the same time. In fact, biogas
production and the stability of the process are highly dependent on waste composition, process
conditions, and the activity of microbial community in the system. In that sense, for certain mixing
ratios, co-digestion may also lead to antagonistic interactions, resulting in methane yields lower than
expected.

By,
Prof. Vinayak Gaikwad

27

CASE-STUDY-OPTIMIZATION AND
MODELING OF HYBRID SYSTEM FOR
TUMNIPADA VILLAGE WITH REAL TIME

DATA

Rural electrification with renewable sources implies rethinking on electrification strategies

taking into consideration economic, social and environmental aspects. In that respect, renewable
distributed generation linked with micro grids presents interesting features for remote or sparsely
populated areas. This paper focuses the residential energy use with the help of micro grid concept for
Tumnipada village, Sanjay Gandhi National Park, Borivali in Maharashtra. The uniqueness of this
project is the use of the renewable energy resources which are easily available such as solar, wind,
biogas or hydro, fuel cell for electricity generation. The paper also covers the main steps in the process
of designing, surveying and modeling of a new micro grid system.

The Electricity sector in India had an installed capacity of 225.133 GW as of May 2013, Worlds 5th
largest. Captive power plants generate an additional 34.444 GW. This generated power constitutes
87.55% of Non-Renewable Power Plants and 12.45% of Renewable Power Plants. Even after such a

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huge generation capacity there is still a huge shortage of power in India. This is due to ever increasing
demand of electricity, drastic achievements in technology, increase in population and also wastage of
electricity. Still more than 40% of rural areas are unelectrified. Our approach is to electrify one rural
area of the remaining 40% mentioned above to provide a small but beautiful home with the facilities
where children can learn at night, farmers or workers can rest with fans on their head and a little bit of
entertainment for children with education on computers. The aim is to power all 36 huts and a
community classroom in Tumnipada, Sanjay Gandhi National Park. Borivali where currently there is
no electric supply from state board. The concept of Microgrid using renewable energy sources (Solar
Energy) is to be implied for electrification of a total load of 500W. The use of solar is due to its
efficiency, readily available and derived directly from sun i.e. free of cost. The other alternative for
microgrid is fuel cell or biogas plant which can be easily installed in this situation.

The term microgrid refers to a single electric power subsystem linked to a small number of distributed
generators that can be powered by either renewable or conventional sources of energy, along with
different load clusters.
 The key feature of microgrids is that they are able to operate independently of the central grid. This

can help improve the power quality and reliability, as well as allow the local community to have
more control over their power network
 The main criteria for distinguishing different kinds of microgrids are as follows
a) Whether it is connected to a central grid
b) What kinds of generation sources are connected to the microgrid.
Depending upon the load profile of a typically located village in National Park, a Micro-grid system
based on locally generated renewable energy sources is to be implemented. Based on the qualitative
and quantitative analysis of geographical conditions of the site and availability of different sources, a
solution is presented. The ability of MG to island generation and loads together has a potential to
provide a higher local reliability than that provided by the power system. To sum up, rural
electrification based on renewable energies in developing countries promises a cleaner, cheaper and
more democratic way of the quality standard of an important section of the world‟s population.

By,
Prof. Pratik Mahale

29

HOW TO SAFELY MANAGE SINGLE-CELL
BATTERIES FOR PORTABLE DEVICES

Rechargeable batteries in general, and lithium-ion batteries in particular, are empowering the

modern age of smart phones, wearable devices and portable applications, making battery management
a critical element of good product design.

Although rare, it is not unknown for portable devices to suffer from overheating, which can often lead
to total failure of the device and, at worst, potential threat to life. While manufacturers seek to avoid
such issues, or to remedy them when they do occur via software or hardware updates, at times this is
impossible and can lead to costly product recalls. Although the cause of overheating may not be
directly linked to battery management, it is obvious that the source of heat is fueled entirely by the
battery‟s capacity to deliver energy. For this reason, managing single-cell batteries in portable devices
should be a high priority for OEMs (Original Equipment‟s Manufacturer).

Getting more from less

Devices are getting smaller, processors are getting faster and user expectations are getting higher. In
many ways these trends are contradictory yet they prevail because OEMs are able to sustain them. But
each one puts more pressure on battery manufacturers to package more power into ever-smaller
dimensions, by pushing boundaries and encouraging innovation. This in turn is helping fuel demand in
the end-markets, specifically smart phones and, more recently but no less aggressively, wearable
devices. The kind of innovation happening in battery technology includes new form factors, 3D
printed materials and the exploration of new chemical compounds. Batteries are now more flexible,
can be manufactured to conform to specific contours or volumes, while still delivering the power
needed to keep our devices running for longer on a single charge. All of this innovation cannot
completely eliminate the fundamental requirement for good battery management, however. Any
battery technology based on a chemical process will inevitably require a solution to managing its
charge and discharge, with particular emphasis on the main threat to and from battery technology.

The chemicals in battery cells do not react well to high temperatures, it accelerates the chemical
process taking place inside the cell, leading to decreased performance and in the worst cases explosion

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or fire. Apart from external atmospheric conditions, several (avoidable) conditions can result in
elevated battery temperatures. These include short-circuiting the terminals and unregulated
charge/discharge current. Measures should be taken to mitigate the possibility of a short across
terminals, at the very least by using thermal/electrical fuses, or diodes, but a better solution would
involve using one of the application-specific battery management devices now entering the market,
which are specifically designed to detect and prevent conditions that could damage single-cell
rechargeable batteries.
Battery cells will have strict parameters for charge and discharge currents. Under discharge
conditions, allowing the cell to drop below a minimum recommended voltage should also be avoided.
Failure to take measures to avoid dropping below a low voltage limit could result in physical damage
to the cell‟s anode base metal. Similarly, over voltage protection should be included, as this too can
lead to irrecoverable damage to the cell. During a charge cycle, the cell is at risk from damage if the
manufacturer‟s current and voltage recommendations are not observed.

Charge, deplete, and repeat

Charging a lithium-based rechargeable cell is comparatively simple, with respect to other rechargeable
battery types such as those based on nickel cadmium or nickel metal hydride. That‟s because it
essentially requires a constant current at a relatively low voltage at the beginning (assuming the cell is
fully discharged) and a constant voltage/trickle current as it nears its maximum charge level.
Achieving this in practice requires the charge voltage/current to conform to the manufacturer‟s
parameters, however. This will impose quite tight tolerances on the voltage and current at the end of
the cycle, as well as a minimum charge voltage during the main period of charging. The current will

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also be specified, often as a function of the cell‟s capacity and the time needed to fully charge it under
ideal conditions. This is known as the C-rate and is used to express the charge and discharge
characteristics of a battery. Although not directly relevant to a cell‟s performance, the design of the
charger will also have an influence on charge cycles and overall battery maintenance. It must consider
how using a battery as a load will influence its behavior, as well as how the charger‟s characteristics
will need to meet the battery‟s requirements. This is why manufacturers will always recommend using
the correct charger for a device. Other design considerations exist for devices with multiple cells, such
as cell balancing, which can further complicate design. Many of the earlier devices that used lithium
ion batteries would have needed multiple cells, such as laptops. However, energy density and
manufacturing techniques, coupled with lower overall system power requirements, means that the
majority of modern portable and wearable devices can generally be powered from a single cell. With a
wealth of experience in managing the complexities of multi-cell designs, OEMs could easily overlook
or underestimate the fact that single cell devices still require proactive cell management and protection
from the numerous conditions that could manifest themselves.

Making safety inherent

While generating the charge voltage and current will be the remit of a power circuit (typically a dc/dc
converter), monitoring the output of the charge circuit as it is applied to the battery terminals should
be entrusted to a separate functional block. This would include detecting an over-voltage and/or over-
current condition during charging, as well as monitoring for possibly dangerous conditions during
normal operation, such as short-circuits across the terminals. As stated earlier, over-discharge is also
detrimental to a battery cell‟s general performance and health, so any monitoring solution should also
check for this condition. Adding this level of functionality into portable and wearable devices is
challenging for several reasons. From an engineering point of view, it will require extra space and
system power; from a commercial point of view it will add cost to the Bill of Materials. Any chosen
solution needs to be small, low power and low cost.

By,
Prof. Sushant Kumar.

32

ELECTROPORATION

Electroporation is a widely used, safe, non-viral approach to deliver foreign vectors into

many different cell types. When a cell is exposed to an electric field of the appropriate strength, the
membrane undergoes reversible electrical breakdown, where transient pores form in the membrane,
which allows molecular transport into the cell. The controlled intracellular delivery of biomolecules
and therapeutics enables the ability to study and engineer fundamental cellular processes and has
therefore been a major focus in biomedical research and clinical medicine. According to Bio Market
Trends, the electroporation market currently represents the second largest segment of the total, $200
million transfection technology market in terms of revenues, behind lipid based technology.
Consumers in the market include those in biomedical research in academic and industry labs and
biotechnology and life science companies who aim to express specific molecules in a variety of cells.
In addition, there is increased interest in using transfection technology clinically, especially with the
advent of CRISPR technology for gene editing.
Successful cell transfection represents the rate-limiting step in numerous biomedical research and bio
production workflows including: cell based therapies, RNA interference screening, and stem cell re-
search. The challenges include variable and poor transformation efficiency, especially with hard-to-
transfect cell lines such as primary cell lines and stem cell lines. One of the traditional bottlenecks to

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electroporation has been obtaining efficient delivery without compromising cell viability. Successful
electroporation involves the optimization of a wide range of electric field and buffer parameters that
are affected by the cell type and molecular payload to achieve an ideal balance of the efficiency of
transfection (how much is delivered) with the damage produced (how many cells are damaged or die).
Protocols are often identified through costly trial-and-error, and can vary significantly from lab-to-lab
and application-to-application. The Rutgers interdisciplinary research and development team are
focusing on translational re-search in developing next-generation electroporation technology for high-
efficiency delivery into cells with superior viability.

Epifluorescence images of cells following delivery of a fluorescent dye, propidium iodide, following
electroporation treatment at varying pulse strengths and duration. Propidium iodide is impermeant to
the cell until the membrane is permeabilized via electroporation. The propidium iodide is then
transported into the cell cytoplasm and fluoresces upon binding cytoplasmic nucleicacid.
The novelty of this report is the impedance detection of membrane permeabilization in a continuous
flow environment at unprecedented sensitivity, an accomplishment not previously reported in
literature. By monitoring changes in the electrical characteristics of individual cells when exposed to
short, high-strength electric fields, the team was able to identify when a cell has become
permeabilized and deter-mine the conditions which led to molecular delivery while preserving cell
viability. This technology will expedite the transfection process by eliminating trial-and-error
electroporation protocol development in a safe and effective manner across cell types and applications.

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A University of Texas at Arlington physics professor has helped create a hybrid nanomaterial that can
be used to convert light and thermal energy into electrical current, surpassing earlier methods that used
either light or thermal energy, but not both. Working with Louisiana Tech University assistant
professor Long Que, UT Arlington associate physics professor Wei Chen and graduate students
Santana Bala Lakshmanan and Chang Yang synthesized a combination of copper sulfide nanoparticles
and single-walled carbon nanotubes. The team used the nanomaterial to build a prototype
thermoelectric generator that they hope can eventually produce milli watts of power. Paired with
microchips, the technology could be used in devices such as self-powering sensors, low-power
electronic devices and implantable biomedical micro-devices, Chen said, "If we can convert both light
and heat to electricity, the potential is huge for energy production". "By increasing the number of the
micro-devices on a chip, this technology might offer a new and efficient platform to complement or
even replace current solar cell technology."

In lab tests, the new thin-film structure showed increases by as much at 80 percent in light absorption
when compared to single-walled nanotube thin-film devices alone, making it a more efficient
generator.Copper sulfide is also less expensive and more environment-friendly than the noble metals
used in similar hybrids. In October, the journal Nanotechnology published a paper on the work called
"Optical thermal response of single-walled carbon nanotube-copper sulfide nanoparticle hybrid
nanomaterials." In it, researchers also say also found that they could enhance the thermal and optical
switching effects of the hybrid nanomaterial as much as ten times by using asymmetric illumination,
rather than symmetric illumination.

.

By
Akshay Karangiya
(T.E.Electrical)

35

LITHIUM-ION BATTERY

A team of engineers led by 94-year-old John Goodenough, professor in the Cockrell School of
Engineering at The University of Texas at Austin and co-inventor of the lithium-ion battery, has
developed the first all-solid-state battery cells that could lead to safer, faster-charging, longer-lasting
rechargeable batteries for handheld mobile devices, electric cars and stationary energy storage.
Goodenough's latest breakthrough, completed with Cockrell School senior research fellow Maria
Helena Braga, is a low-cost all-solid-state battery that is non-combustible and has a long cycle life
(battery life) with a high volumetric energy density and fast rates of charge and discharge. The
engineers describe their new technology in a recent paper published in the journal Energy &
Environmental Science.

"Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven
cars to be more widely adopted. We believe our discovery solves many of the problems that are
inherent in today's batteries," Goodenough said. The researchers demonstrated that their new battery
cells have at least three times as much energy density as today's lithium-ion batteries. A battery cell's
energy density gives an electric vehicle its driving range, so a higher energy density means that a car
can drive more miles between charges. The UT Austin battery formulation also allows for a greater
number of charging and discharging cycles, which equates to longer-lasting batteries, as well as a
faster rate of recharge (minutes rather than hours).

36

Today's lithium-ion batteries use liquid electrolytes to transport the lithium ions between the anode
(the negative side of the battery) and the cathode (the positive side of the battery). If a battery cell is
charged too quickly, it can cause dendrites or "metal whiskers" to form and cross through the liquid
electrolytes, causing a short circuit that can lead to explosions and fires. Instead of liquid electrolytes,
the researchers rely on glass electrolytes that enable the use of an alkali-metal anode without the
formation of dendrites. The use of an alkali-metal anode (lithium, sodium or potassium) -- which isn't
possible with conventional batteries -- increases the energy density of a cathode and delivers a long
cycle life. In experiments, the researchers' cells have demonstrated more than 1,200 cycles with low
cell resistance. Additionally, because the solid-glass electrolytes can operate, or have high
conductivity, at -20 degrees Celsius, this type of battery in a car could perform well in subzero degree
weather. This is the first all-solid-state battery cell that can operate under 60 degree Celsius.
Braga began developing solid-glass electrolytes with colleagues while she was at the University of
Porto in Portugal. About two years ago, she began collaborating with Goodenough and researcher
Andrew J. Murchison at UT Austin. Braga said that Goodenough brought an understanding of the
composition and properties of the solid-glass electrolytes that resulted in a new version of the
electrolytes that is now patented through the UT Austin Office of Technology Commercialization. The
engineers' glass electrolytes allow them to plate and strip alkali metals on both the cathode and the
anode side without dendrites, which simplifies battery cell fabrication. Another advantage is that the
battery cells can be made from earth-friendly materials. "The glass electrolytes allow for the
substitution of low-cost sodium for lithium. Sodium is extracted from seawater that is widely
available," Braga said. Goodenough and Braga are continuing to advance their battery-related research
and are working on several patents. In the short term, they hope to work with battery makers to
develop and test their new materials in electric vehicles and energy storage devices.

By,
Harsh Palja (T.E. Electrical)

37

HUMAN MACHINE INTERFACE

With the introduction of IEDs (Intelligent Electronic Devices), the traditional switchboard

interface is being replaced by Human Machine Interface (HMI) software loaded on computer
hardware. The designer has a wide choice of HMI vendors that support a wide range of functionality.
HMI software may be tightly integrated into a hardware platform such that when the HMI is ordered
the software is actually an option for the hardware. HMI substation designer should use this technical
article to determine some of the important criteria for both the hardware and software components of
an HMI that should be specified for the system
HMI Hardware
The choice of any hardware that does not meet IEEE Std 1613 requires that the designer provide
additional system design requirements for at least the following three items:

1. Isolation of the computer from the substation battery and AC systems by using an inverter or
other device that meets IEEE Std 1613.

2. Isolation of the communication ports from interference generated in the substation
environment by using fiber optic transceivers or other intermediate device that meets IEEE Std
1613.

3. Installation of heating and cooling systems those are remotely monitored and alarmed such that
temperatures beyond the computer rating are remotely indicated.

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HMI software can be divided into the following three categories:
a. Operating system software
b. Application software that includes any application loaded on the computer
c. Configuration file(s) for the settings, displays, and database of the HMI application

Note that the HMI computer may have other applications that also have configuration files, but the
specification of these applications and files are not included in this standard
HMI screens
The HMI application provides a series of screens or windows for the monitoring and control of
substation devices. The designer should specify either all, part, or additional minimum requirements

Alarm annunciator that displays real-time alarms that can be sorted, filtered, individually disabled or
enabled, and silenced based upon multiple criteria such as alarm name, group, and time.
HMI control capabilities
The HMI application includes the capability of controlling equipment. The designer shall specify if
HMI control is required. When control capabilities are required, they may include a combination of at
least the following:

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a. Keys and switches (alphanumeric or function, or both)
b. Cursor (mouse, trackball, or key controlled).
c. Poke points (defined display control selection points)
d. Pull-down or pop-up menus
e. Physical switches, meters, lights, etc.

Other features of HMI

The HMI application will typically provide other features that include report generation from any
historical or real-time measurement or status point, log files, links to documentation, help files that are
context sensitive, multiple users, multiple security levels, symbol templates, symbol libraries, multiple
protocol support, printing, etc. In addition to the HMI software, the designer should also
consider other software applications to be loaded on the computer. Examples of such applications
include software that configures substation devices, monitors network traffic, retrieves data from
substation devices, views different files, web browsers, and other applications that may be important
to personnel working in the substation. These applications may or may not be directly linked in the
HMI application. The designer should also consider whether the actual configuration files should
have backup files located on the substation computer or if the files should be stored elsewhere. Due to
availability, security, and redundancy, this determination may not be trivial and should engage all of
the impacted parties.

How HMI used to be…

User interfaces at power substations first started out as a switchboard interface long time ago. This
was an assemblage of instruments, indicators, annunciators, switches and associated hardware placed
on the relay panels or switchboard in such a way as to represent the electrical connectivity and
operating condition of the substation. These devices were connected directly to control and monitoring
circuits of power equipment. The operation of equipment through this interface was generally
restricted to operators or their delegate. However, the time has made this switchboard interface old
and not usable any more…

By,
Mayuri Sonawane
(T.E.Electrical)

40

WIRELESS POWER TRANSMISSION

Electricity energy needs to be transported to the distribution lines through cords. One of the

major issue in power transmission is the losses occurs during transmission and distribution process of
electrical power due to the energy dissipation in the conductor and equipment used for transmission.
As the demand increase day by day, the power generation and power loss are also increased. In order
to minimize power losses in the power distribution network, wireless power transmission has been
known for centuries to clean sources of electricity. Wireless power transmission, also known as
inductive power transfer, can be used for short range or even long range without cords. This
technology provides efficient, fast, and low maintenance cost as compared to previous technologies.

The founder of AC electricity, Nikola Tesla, was first to conduct experiments dealing with WPT. His
idea came from the notion that earth itself is a conductor that can carry a charge throughout the entire
surface. While Tesla‟s experiments were not creating electricity, but just transferring it, his ideas can
be applied to solve our energy crisis. Each application has its respective drawbacks but also has the
potential to aid this planet in its dying need for an alternative to creating power. There are two
techniques in wireless power transfer, which are near-field technique and far-field technique. In
general, far-field techniques provide lower frequency transmission with simple pattern measurements
and near-field technique with higher frequency transmission and complete pattern measurements.

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Near-field Techniques-
- Electromagnetic (EM) Radiation:
- Inductive Coupling:
- Magnetic Resonant Coupling:
Far-field Techniques-
-Microwave Power Transmission (MPT):
-Laser Power Transmission
Applications depend on the uses of low power devices that can be wireless sensor or different
electronic mobile devices, power range (less than 1W) and high-powered devices in the field of
industrial area, power range (not more than 3KW).

By,
Rahul Shirsat
(T.E. Electrical.)

42

HIGH POWER SUPERCAPACITORS FROM
CARBON NANOTUBES

Supercapacitors are electrical storage devices that can deliver a huge amount of energy in a

short time. Hybrid-electric and fuel-cell powered vehicles need such a surge of energy to start, more
than can be provided by regular batteries. Supercapacitors are also needed in a wide range of
electronic and engineering applications, wherever a large, rapid pulse of energy is required.
Ning Pan, a professor of textiles in the Department of Biological and Agricultural Engineering and the
Nanomaterials in the Environment, Agriculture and Technology (NEAT) center at UC Davis,
postdoctoral researcher Chunsheng Du and Jeff Yeh of Mytitek Inc. of Davis prepared suspensions of
carbon nanotubes -- tiny rolled-up cylinders of carbon just a few atoms across. They developed a
method to deposit the nanotubes on nickel foil so that the nanotubes were aligned and packed closely
together.

43

Conventional, or "Faraday" capacitors, store electrical charges between a series of interleaved
conducting plates. Because of their small size, the nanotubes provide a huge surface area on which to
store and release energy, Pan said.
The new devices can produce a power density of 30 kilowatts per kilogram (kW/kg), compared with 4
kW/kg for the most advanced devices currently available commercially.

By
Prof. Vinodkumar Pal

44

Happy Makers of Electrotrend…

ELECTROTREND is a magazine of new trends in
electrical engineering and its broad areas. The magazine
covers various prospectives. It also includes various articles
on recent technologies given by faculties and students of
electrical engineering department. The editorial board is
very happy for presenting the first issue of electrotrend.

Magazine Advisor- Prof. Bhushan Save
Faculty Editors - I) Prof. Vinayak Gaikwad

II) Prof. Piyali Mondal
Student Editors- I) Miss. Mayuri Bankar (TE Electrical)

II) Miss. Ruchira Khairnar (TE Electrical)
III) Mr. Vishal Maru (TE Electrical)

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