Working principle of Generators
Generator plays a vital role in power system.
Faraday’s law of electromagnetic induction forms the working principle of
electrical generator, which states that, EMF generated in a conductor which is
placed in varying magnetic field. In a generator a uniform magnetic field is
generated and a prime mover is employed to create uniform motion and thus
Function of Generators
have many functions, the primary function being generating power. The generated
power is transmitted by transmission line and distributed using distribution
system. Their function also includes maintain the frequency in the grid, not
maintaining the frequency may have catastrophic effects on the grid.
Laws of electromagnetic induction
first law states that, any change in magnetic field causes an EMF in a
conductor which is placed in a magnetic field.
second law states that the induced EMF is equal to the change in flux linkages.
Right Hand Rule
clenched Right Hand, thumb, index finger and middle finger are opened in such a
way that all three fingers are perpendicular to each other. Then, the thumb
denoted the direction of motion, Index finger denotes the direction of the
field and the middle finger denotes the direction of current.
Production of EMF in coil one which is
magnetically coupled with coil two, when there is a change in current in coil two
is called mutual induction.
EMF produced is given by
We know that,
Transformer Voltage Ratio
Transformer voltage ratio or turn’s ratio is
the ratio of number secondary turns to primary turns. The ratio determines
whether the transformer is either step up or step down. Ratio is also given by the ratio of secondary
voltage to primary voltage thus also called voltage ratio turn’s ratio or voltage
ratio is used for designing the Transformers.
Power is the power consumed by AC circuits is not in phase with the
voltage. When the current passes through a capacitor and inductor the power is
stored and released alternatingly, creating an illusion that the element is not
consuming power. But in reality they have voltage drop across them capacitors indicating
a power called reactive power. Capacitor generate reactive power while
inductors consume reactive power. Reactive power is unavoidable in an AC
Causes of Low Power Factor In Electrical System
The main source of low power
factor are inductive loads as a pure inductive load lag current by 90 degree
from voltage. And thus reducing the power factor but completely avoiding
inductive load is impossible. As every wire has inductance.
Improving Power Factor
Power factor improvement is very
important and there are various ways to improve power factor.
Purely inductive loads causes
current to lag by 90 degrees and capacitors cause current to lead by 90 degrees
by connecting capacitors in parallel to the electrical system power factor can
An unloaded three phase
synchronous motor has capacity to run on any power factor, leading lagging on
unity depending on the excitation. Thus Buy running synchronous Motors in over-excited
mode cause an increase in reactive power or improve power factor.
Induction motor cause lagging
current as the exciting current is inductive in nature. If the excitation
current is produced by an external source called the phase advancer, the power
factor can be improved.
Linear load is highly stable as
there is no disturbance or harmonics caused by them. The system can reach equilibrium when there
is any disturbance easily, as the current varies linearly with voltage.
They have high efficiency as
there is no or less phase difference between voltage and current are there is no
or less reactive power from the formula.
We can thus conclude that the
efficiency is high
The power factor for Linear load
is one or close to 1 they are high, as the linear loads have current and
voltage varying proportionally they produce no or less phase shift thus maximum
The stability of the system is
less as nonlinear systems have current varying from voltage nonlinearly usually
having spikes. Thus causes transient in
the system and makes the overall system unstable.
Efficiency is comparatively low
as the reactive power comes into the picture, due to the bearing variation of
current from voltage. Which reduces real power and decreases the transmission
The power factor is also
negatively affected power factor fluctuates as the current varies with the
voltage. When the current lead or lag the power factor reduces or increases.
Power Industry Trends in India
When it comes to power industry
India has seen a continuous growth.
Power in the past, like about a hundred years ago, was not as widely
used it as it is now. But still Electricity was used, usually they had
microgrids. Power was introduced in India 10 years after it was introduced in
London and 17 years after it was introduced in New York. The first hydroelectric
generator was Sidraony power station in Darjeeling with capacity of 130
kilowatts, then other energy sources like thermal power and wind energy came
The introduction of nuclear power was a big change in power industry. Although there is a controversy on whether
the nuclear power is good or bad. It is
undeniably an advantage when it comes to the power generation. There is also increase
in Wind and solar energy though we have less efficiency.
In future India’s consumption of
power will become independent of non-renewable energy, as it is a long known
agenda to make India a green country. There will also be new technologies in
future which will improve the efficiency of solar cells bringing it to 80%-90%
from the present 30%-40%.
Impacts of power generation when employing coal as fossil fuel.
Employing coal as fossil fuel has various adverse effects on human and
Burning of coal causes various health problems.
Beginning with the extraction of coal, a process called as mountaintop
extraction, trees in the entire mountain is cut down, killing the animals and
destroying the ecosystem.
The coal is extracted by blasting the top using dynamite which causes
thousands of tons of waste which gets mixed with the stream contaminating drinking
They also create smog dust which causes asthma and various breathing
The health effects alone costs 100 billion dollars in USA.
Mercury is a waste that is produced as a by-product, it damages nervous
system causing underdevelopment, when babies and young children are infected.
When mercury is released in water supplies fishes consume it, which
affects human seafood.
Every year coal power plants generate a 140 million tons as cool as
which are dumped in pits across the world.
Living near coal Ash is same as smoking a pack of cigarettes every day.
It is important that we understand the consequences of coal in power
generation, we must reduce coal in power generation and turn towards Clean
Energy like solar energy wind energy.
Benefits of Solar Energy
Solar energy is water conservation.
Solar energy in any form requires very less or no water in its
Solar energy is green and does not require cutting down of any trees,
solar plants and trees can grow side by side.
The amount of energy received per minute is enough to power the human
Civilization for 6 years.
Solar panels are made of silicon which are found abandoned in
There are large deserts where solar panels can be placed to increase the
efficiency of the energy production.
There are new technologies like
concentrated solar plants which can also be employed to increase the
There is area for Research and improvement on solar cells in future.
The Utilisation of Solar Energy
Is Limited By the Following Factors
Solar cell production is expensive as it require Silver which is precious
metal also the production has to be done in clean rooms.
Today modern technology has only
come for enough to make the solar cells 20 to 30% efficient.
We do not know the effects of harnessing solar energy in large quantity
as the ground may not receive the amount of solar energy which is usually
received from the Sun.
Availability of solar energy 24
hours is not possible.
Solar energy is moody as it
depends on climate which is unpredictable.
The nuclear plant is located in. Soviet Union (Ukrainian Soviet
This nuclear Plant was
commissioned on 1977 and accident occurred on 26th of April 1986.
International nuclear event scale agency gave level 7 it was the first
plant to get level seven.
The plant operated for 9 years giving a net electrical power of 3700MWe,
and had RBMK-1000 Reactor.
The maximum radiation detected was 300sv/h and affected area of 500
kilometres and relocated 335,000 people.
There were 169 direct fatalities, the plant decommissioning process
began in 2016.
The accident was caused by human
error violation of procedure running unauthorised experiment, by an improper experiment
the plant became prompt critical causing a blast with in the reactor.
The nuclear plant is located in Japan.
This nuclear Plant was
commissioned on 1971 and accident occurred on 11th of March 2011.
International nuclear event scale agency gave level 7.
The plant operated for 40 years giving a net electrical power of 4564MWe,
and had BWR-3 and BWR-4 reactors with mark 1 containment vessel.
The maximum radiation detected was 200sv/h and affected area of 40
kilometres and relocated 150,400 people.
There was no direct fatalities, the plant decommissioning process will
take 30 to 40 years.
the accident was caused by a large Tsunami which the nuclear power plant
was not designed to handle the tsunami destroyed the cooling system and the
backup power supply passing a partial