HVDC TRANSMISSION LINES INDIA

This post is about the HVDC Transmission Lines in India. I must thank Priya for asking electrical question regarding HVDC links.Hope it would be useful for the budding Electrical Engineers.Whenever we think about HVDC links,many questions comes to our mind.Some of them are 1.Why we should go for HVDC transmission instead of AC Transmission? 2.Does India has any HVDC links? If yes, how many and where are these HVDC links located ?

First of all,HVDC transmission is adopted whenever there is need for power transmission over longer distances.We must have heard the term "Break even Distance".It is the distance at which the cost for AC Transmission and the Cost for DC Transmission are equal.Usually it is around 600KM.Taking the distance, future requirements,cost saving and various other factors into considerations the HVDC links are set up.

To know the list of HVDC links in india click the below link.
http://online-electrical-engineering.blogspot.com/2012/01/hvdc-lines-in-india.html

ELECTRICAL QUESTIONS AND ANSWERS PART1

In web i came across a Electrical Question which says "Is it possible to make Electricity from the Ceiling fan?".The answer for this question is yes,you can make electricity using the ceiling fan.But Another question arises here,"Will the Output Electrical Energy from the fan would be more or equal to the supply given to the fan ?"

The answer for this question would be a definite NO.Let us see how the answer is justified.As we know that Energy can neither be created nor be destroyed.It is transformed from one form of energy to another form.The idea of placing a rotating magnet attached to the base of the fan and coils to the hook and try to generate electricity will not work out.

The reason for this is there will be a increase in the weight of the fan which would result in drawing more load current to run the fan at the same speed before attaching the rotor.So when input increases automatically efficiency comes down.Next having a magnet near the electrical wires would cause hysteresis loss and eddy current loss.Therefore if you sum up the output electrical energy and mechanical energy,it will be always less than your input electrical energy.

If you see renewable energy resources,the energy is taken as it is from the nature.For example,As the wind blows,we make use of it and we do not blow the wind and take electricity.In hydel power plants we use the potential energy stored in dams for generating electricity.So the idea of taking electricity from moving car,fan etc would be a failure.