QUESTION induced E.M.F and current. FIRST LAW: Whenever
principles and functions of a Generator in a power system layout.
The generator is an electric device used for converting
mechanical energy into electrical energy. Actually the generator does not
create electrical energy , it helps in
the flow of movement of electric charges which results in electric current.
Later , Faraday discovered that generator works on the
principle of electromagnetic induction.
He discovered that the flow of electric charges could be obtained by
moving the conductor containing electric charges in a magnetic field. This creates the potential difference between
the two terminals of the electrical conductor which in turn produces electric
Generators are very useful electrical device used for
suppling electrical power. Discontinuity of daily activities and business works
disruption can be prevented by using generators.
? Laws of Electromagnetic Induction and the rule which states the
direction of induced E.M.F and current.
FIRST LAW: Whenever a conductor is rotated in magnetic field
emf is induced which are induced emf.
SECOND LAW: Induced emf is equal to the rate of change of
The rule stating the direction of induced emf and current
is given by Flemings right hand rule.
FLEMING’S RIGHT HAND RULE
Thumb – direction
of the motion of the conductor relative to the magnetic field.
First finger – direction of the magnetic field. (north to south)
Second finger – direction of the
generated current within the conductor.
? Mutual Induction in a Transformer along with the E.M.F equation and
Voltage Transformer Ratio.
AC supply is applied to the primary winding of the
transformer. This alternating current produces alternating flux in the core
which induces emf in the secondary due to the mutual induction. Magnitude of this induced emf can be found by
using the EMF equation of the
RMS induced emf in primary winding (E1) can be
E1 = 4.44f N1
Similarly, RMS induced emf in secondary winding (E2) can
be given as
E2 = 4.44f N2
eq 1 and eq 2 are the emf equation of transformer.
VOLTAGE TRANSFORMER RATIO:
As the secondary voltage increases, the number of turns
in secondary also increases and vice versa since it is directly propotional.
Similarly for primary side.
What is reactive power
Reactive loads such
as inductors and capacitors are usually said to dissipate zero power but
actually it draws a little current and voltage drop so that it dissipates
power. This power is called reactive power.
causes low power factor in Electrical System
1) Inductive Loads: Machines using
inductive loads draws magnetising current to produce the magnetic field and hence work at
low power factor.Current drawn in inductive loads is lagging.
2 Due to improper wiring or electrical accidents.
3) Variations In Power System Loading:When the
system is loaded lightly, the voltage increases and the current drawn by the
machines also increases.
4) Industrial heating furnaces.
3. How to
improve Power Factor
1)Using capacitor banks
2) Improvement can be done by using synchronous
condenser which is nothing but a over excited synchronous motor which draws
3) Using phase advancer: To improve pf, supply
lagging current from an alternative source. This alternative source is
the phase advancer.
Research and explain how in a transmission system,
the stability and efficiency, and Power Factor of the system are affected by
the type of connected load. Elaborate the above specifically with respect to
linear and non-linear loads (like power supply rectifier, electric welding
machine, or arc furnace).
Capacitive load in three phase is used to raise the power
factor, since the circuit current in capacitive circuit leads the supply
voltage. Since most loads are inductive, and making the cosine of that angle to
be higher i.e. approaching unity, moreover reducing the reactive power, which
does no job in a circuit, other than flowing to and fro causing overheating.
For purely resistive loads, the “angle” between
them is now zero – and the cosine of zero is unity.Due to usage of non linear
loads and power electronic equipments in power system transmission,
distribution and utilization sectors leads to distortion in voltage and current
Stability will be too good for linear loads. Balanced
stability for all linear loads whereas it will be too worst for non-linear
For non-linear loads,
input power will be large so that the efficiency will be too low. But
for linear loads the efficiency will be too good.
Discuss the past, present, and future trends of power industry in
respect to a particular country, for example, your own country.
The first hydroelectric installation in India was
installed near at Sidrapong in 1897. The first electric street light in Asia
was lit on 5 August 1905 in Bangalore.In 1971, India set up its first pressurized
heavy water reactors with Canadian collaboration in Rajasthan. In 1987, India
created Nuclear Power Corporation of India Limited to commercialize nuclear
power. India’s electricity generation
from 1950 to 1985 were very low when compared to developed nations. Since 1990,
India has recorded faster growth in electricity generation. HVDC 500 kV back to back was introduced in the
•Access to ‘electricity for all’
• smart grid systems and application.
In 2011, The Wall Street Journal discovered a new mine of uranium in India,
the country’s largest ever.On August
2015, Cochin International Airport became the world’s first fully solar powered
The year 2016 started with steep fall in the
international price of energy commodities such as coal, diesel oil, naphtha,
bunker fuel and LNG which are used in electricity generation in India.
The contribution from natural gas, oil and hydro
plants has decreased in the last five years (2012-2017).
Future Outlook for Changing Indian Power Sector
•Reduction of T&D losses to below 10 % in all
utilities •Infrastructure and standards for electric vehicles•1,200 kV ac
system in operation •Export of smart grid products to overseas•33 % or more
renewable in power system •Export of Smart Grid products, solutions and
services overseas •IT network and CRM system for electric utilities.
India’s government is also developing up to 62, mostly
thorium reactors, which it expects to be operational by 2025.
In order to supply the future demands of
individual fuels of the different sectors , the study considers two fuel mix
scenarios for the gross generation of electricity.
Discuss environmental impacts of power generation from fossil fuel,
especially the impacts by coal-fired power plants.
Coal combustion waste is the nation’s second largest
waste stream after municipal solid waste. During the mining process coal dust
are stirred up and released while transportation which leads to deadly
Coal-fired power plants are the huge contributor to
global warming. Black carbon resulting from incomplete combustion is an
additional contributor to climate change.
temperature rise and accelerating sea level rise as well as increasing
risks of drought, heat waves and species loss.
Methane (CH4) often present in the same areas that
coal is formed and is released during mining activities. Methane is 34 times
stronger than CO2 which results in global warming.
Radioactive materials like uranium and thorium occur
in minor quantities in the coal. When coal is burned, the fly ash contains
uranium and thorium “at up to 10 times their original levels” which
is not good for the environment.
Coal contains nitrous oxides which may leads to lung irritation, pneumonia and
When the sulfur in coal reacts with oxygen, SO2
combines with other molecules in the atmosphere to form small acidic
particulates that can penetrate human lungs which may cause asthma, bronchitis,
smog, and acid rain.SO2 also damages crops and acidifies lakes and streams
which leads to imbalance in ecosystem.
Coal has mercury which can damage the nervous,
digestive, and immune systems.
List benefits of solar energy. Also explain why with so many benefits,
the utility and infrastructure development of solar energy generation is
BENEFITS OF SOLAR ENERGY:
The most important benefit of solar energy is that it
is truly renewable energy source. It can be harnessed in all areas of the world
and is available every day at free of cost.
Electricity bill will drop and also we can save more
energy for future use.
Now a days, Solar energy can be used for diverse
purposes from distilling water to power satellites in space.
Maintenance and repair work is very low.
Installing solar panels on rooftops helps combat
greenhouse gas emissions and also reduces the dependence on fossil fuel.
Solar City’s carbon footprint per unit of energy
production is 95% lower than that of coal fired power plants.
Solar energy reduces respiratory and cardio health issues.
The utility and infrastructure development of solar
energy generation is limited because
The initial capital cost of purchasing a solar system
setup is fairly high.
The efficiency of the solar system drops for different
Solar Energy Storage Is Expensive
There are also some toxic materials and hazardous
products used during the manufacturing process of solar photovoltaics , which
can indirectly affect the environment.
It is not 100% reliable i.e. without
sunshine no generation of electric current.
Complications when de-installation and re-installation .
Compare the accidents of Chernobyl disaster (1986) and Fukushima (2011)
in relation to nuclear power generation.
Chernobyl accident is one of the huge nuclear plant
disaster happened in the year 1986.The main root cause of this accident was due
to unsafe reactor design. The reactor was build up with the radioactive
materials which was drastically released
during explosion and due to uncontrolled power surge fire occured. The
uncontrolled power surge was due to several reasons like increased power and
disabled safety systems.The main reason for this accident is flawed reactor
design combined with human error. Due to explosion the reactor sent
radioactivity into the atmosphere.
Fukushima accident was happened by an earthquake and
the reactors still have the containment vessels surrounding that nuclear cores .At
fukushima , the earthquake of 9 magnitude and tsunami crippled power plant’s
cooling system. It leads to the partial melting down of the reactor.
Temperature at the bottom of the reactor and the pressure vessels have
decreased to well below boiling point but are stable. Access to all three reactor buildings has been
gained, but dose rates remain high inside. Nitrogen is being injected into all
three containment vessels and pressure vessels. Tepco declared “cold shutdown
Research and elaborate on the benefits of using Natural gas for power
generation and substantiate with data to highlight that this energy fuel is
gaining popularity in country like Australia.
Natural gas is environmentlly very clean. It is the
cleanest burning fossil fuel which produces very few pollutants into the
atmosphere. It doesn’t leave behind any unpleasant ash, or odors. If inhaled in little amounts
natural gas is non-toxic or harmful to humans.
Natural gas is economical and efficient. An odorant is
added to natural gas by the producer if the smell of gas is detected, it
signals that a leakage exists and should be corrected immediately.
Figure 1: Australian energy production, by fuel type
Natural gas production rose by 5 per cent,
underpinned by increased coal seam gas (CSG) production. CSG production
accounted for 18 per cent of national gas production and nearly half of eastern
market gas production in 2014–15.
Natural gas generation fell by 4 per cent
in 2014–15, a result of capacity closures and higher gas prices. Gas accounted
for 21 per cent of total electricity generation in 2014–15.
Table 2: Australian energy production, by fuel type
Average annual growth
Oil and NGL
From the data discussed above it is cleared that the
natural gas is gaining popularity in Australia and it is cleanest of all fossil