Working principles and functions of a generator in a power system layout

A country’s development is identified by the amount of power generated. The conventional and non- conventional sources serve this purpose. But as the time is passing the amount of pollutants produced from conventional sources is also increasing day by day. There is a constant search for combining conventional ideas with the new clean energy source methods, leading to a brand new area of technology. Solar energy is a never depleting source of power. Transmission is monitored regularly so that the losses are minimal. Nuclear energy is a new concept and it employs the power of atoms and sub- atomic particles to generate energy which is also clean. But, recently our world have seen many disasters as a result of mishandling. Natural gas, although a conventional source, yet it’s considered ‘clean’. It is limited though. Many countries have employed the use of natural gas and are running a pollution- free program.

AC generators are being used in almost all power generating plants. These work on the phenomenon known as ‘Electromagnetic Induction’. This was proposed by M. Faraday which states that if any conductor is rotated in a magnetic field of some strength, then a voltage is induced in the conductor and if it is a closed circuit then a current is also flows through the conductor.AC generators are of two types, namely induction generators and synchronous generators. Synchronous generators are used in power systems.

According to Law of Electromagnetic Induction, if a coil is kept in a changing magnetic field, then a voltage is induced in it and if the circuit is closed, the current will also flow. It was proposed by M. Faraday and is given as,

E= -N*(d Φ/ d t)

Where, ‘E’= induced voltage in (volts)

 ‘N’= number of turns in the coil

‘d Φ’= change in magnetic flux (in weber)

‘d t’= change in time (in seconds)

‘d Φ/ d t’= rate of change of magnetic flux

For determining the direction of the induced current, we follow ‘Lenz’s law’. According to it, the direction of the induced voltage (and hence the current) is such that it opposes the cause producing it. In this case the magnetic field  (Gerbis, 2018).

In a transformer, the two coils are wound on the same magnetic core. When AC current in supplied to the primary coil, being fluctuating in nature, it varies the magnetic flux linked with the primary coil and induces a voltage in the secondary coil. This phenomenon is called as ‘mutual induction’. Suppose ’i1’ current flows through the primary coil, ‘Φ12’ is the flux linking with the secondary coil when ‘i1’ flows through the primary coil, ‘N2’ be the number of turns in the secondary coil, then the mutual inductance of secondary coil with respect to the primary coil would be,

Laws of Electromagnetic Induction and the rule which states the direction of induced E.M.F and current

M12= (N2*Φ12)/ i1

Similarly, M21= (N1*Φ21)/ i2

Let the EMF induced in the primary winding be ‘E1’ and EMF induced in the primary winding be ‘E2’. So, E2/ E1= N2/ N1= K will be called as the EMF equation of the transformer and ‘K’= transformation ratio (Electrical Technology, 2014).

Whenever we consider any purely resistive circuit in either DC or AC, the formula for the power is given by, P= E rms*I rms.

Where, ‘E rms’ is the root mean square voltage and ‘I rms’ is the root mean square current.

But, in the case of an AC reactive circuit, this product is greater than the true power. This excess power is called as reactive power.

Some of them are:

• Inductive load plays the most important part in low power factor in electrical systems. Currents lags behind voltage in a purely inductive circuit by 90 degrees, making the power factor zero.

• Load in any power system is not constant. In the ‘No load’ condition, the input voltage is increased, which in turn increases the current as well and hence low power factor.

There are many ways through which the power factor can be improved.

• Phase advancers can be used to improve the power factor. It supplies the ampere turns which generates flux which reduces the phase difference between the voltage and current.
• A group of capacitors can be installed in parallel to the inductive loads (in most of the cases the load in inductive in nature) so that it provides the necessary reactive power for them to operate.

3. Due to switching on and off of the load the stability of the transmission lines changes or we can say due to variation in the load. Steady state stability is defined as the ability of the transmission line to bring itself back to normal after little fluctuation in the load. These fluctuations, either increasing or decreasing in nature, makes the transmission line instable. A transmission line can be imagined as connection of capacitances and inductances. Transmission efficiency is the ratio of receiving power to sending power, expressed in percentage. The receiving power is inversely proportional to the load current. If the load is removed, the current increases and hence the receiving power decreases and so the efficiency decreases and vice versa. If the load has capacitance, the power factor is decreased, making the system inefficient. Whereas, if the load has inductance then also the power factor decreases.

4. India has been one of the fastest growing nations across the world in power sector. Earlier India was reliable almost completely on the conventional sources of energy such as coal. A new scheme is currently operating which involves renting roofs of the residential and commercial infrastructures for installing solar panels in which some part of the power will be taken by the government, while giving advantage to the operators as well. Wind energy is currently the largest source of power generation in the country, helped India to rank 3^rd globally in terms of electricity generation (India Brand Equity Foundation, 2018).

With such a pace, India is definitely going to make its firm hold in renewable energy generation. Many schemes and programs are going to be implemented in the near future. India is very serious about environment and hence will try to achieve this at a faster rate

Mutual Induction in a Transformer along with the E.M.F equation and Voltage Transformer Ratio

5. Fossil fuels comes under the category of ‘non- renewable’ sources of energy. They are one of the prime factors which is degrading the environment. Earlier when the technology was not present as of now, fossil fuels, such as petrol, coal and other hydrocarbons were used almost everywhere. But now with the advancement of technology, the use of coals is decreasing because it leads to emission of harmful gases such as, CO2, NO2, SO2, methane. These all are the prime greenhouse gases leading to greenhouse effect.

Acid rain is corroding almost every monument of this world. Depletion of ozone layer is causing skin cancer. Moreover, the emission of gases from the power plants is causing asthma, bronchitis among humans as well as animals.

6. Solar energy is undoubtedly one of the biggest and important source of power because earth lies in such a position where we get adequate amount of sunlight. Currently we are successful in using 1% of the total solar energy received. Solar energy is a clean source of energy. It doesn’t require much efforts in installations as compared to wind and hydro- power plants. But, still needs a lot of open areas. It can be used directly in heating purpose such as in solar furnaces and solar water heaters. It is noiseless and a free source of energy, leaving no carbon footprint. One of disadvantages of solar energy is its inconsistency. Solar light is not constant throughout the day and this creates a problem to those areas which needs continuous power. Another reason that is making it a limited source is the unavailability of the materials required to produce solar cells. Cadmium telluride is used which is a rare element.

7. Undoubtedly, the disaster caused due to Chernobyl as far more than that of Fukushima. Both released radionuclides (such as noble gas and iodine). But, the amount of actinides released during Chernobyl was tremendously high. If the magnitude of the release of these refractory elements are to be compared, then Chernobyl clearly contributed approximately 4 times more than Fukushima. The impact of Chernobyl was much more as this can be clearly shown by the after effects on the health of the people. The health of the people of Japan was much less disrupted as compared to that of Chernobyl accident. The radioactive actinides due to Chernobyl was deposited over Pacific Ocean, disturbing the aquatic life as well. One more important factor that made the impacts of Fukushima less destructive was the campaigns that worked quickly and saved many people.

8. Natural gas is being used widely for over 100 years in Australia. Natural gas produces half the carbon content which means it doesn’t harms as badly as coal or any other non- renewable source. It is termed as a ‘flexible fuel’ because it is available 24×7. It is successfully meeting the energy demands of Australia. It is used by many plants to generate electricity. Natural gas can be easily shipped by liquefying it. Australia has a reserve of over 3921 billion cubic meters of natural gas. Australia produced around 66 billion cubic meters of natural gas in the year 2014- 2015. Australia also produces LNG. It exported around 10.7 billion cubic meters in 2004. The electricity produced due to gas is being maintained around 20% each year in Australia which is considerable. Australia is going to witness many upcoming projects on natural gas in the coming year. All these stats clearly shows that Australia is growing fast in this source of energy.

Conclusion

From this assignment I have concluded that energy plays an important role in the growth of any country and not just any source, ‘non- renewable sources’ are the future of the world. Countries like India are constantly growing in the areas of ‘clean’ energy sources. Australia on the other hand is using natural gas as one of the main energy sources. With advancement in the technology there comes proper monitoring, proper care. Mishandling of anything causes disasters. Power generation has to be done in a wise manner as well as without polluting the environment. The proper care and assessment will lead to reduction in the tragedies along with the justified use of the resources. Future lies in the hands of those countries who have recognized this aspect of development in the area of power industry.

References 

Electrical Technology. (2014, March 28). EMF Equation Of the Transformer. Retrieved from https://www.electricaltechnology.org: https://www.electricaltechnology.org/2012/02/emf-equation-of-transformer.html

Gerbis, N. (2018, August 19). How Induction Cooktops Work. Retrieved from https://howstuffworks.com: https://home.howstuffworks.com/induction-cooktops2.htm

India Brand Equity Foundation. (2018, August 7). India Power Sector Analysis. Retrieved from https://www.ibef.org: https://www.ibef.org/industry/indian-power-industry-analysis-presentation