Electric Train
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Electric Train, Working, Block Diagram, Advantages, Disadvantages

Posted on by Chetan Shidling

Hello guys, welcome back to my blog. In this article, I will discuss what is an electric train, working on an electric train, block diagram, advantages, disadvantages, applications, conclusion, etc.

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Electric Train

An Electric train we generally call it as Electric locomotive. The name electric locomotive indicates that, the system which uses electrical power to drive the locomotive.

Usually, before talking about an electric locomotive we thought that how it looks or how it works, and Is there any advantages or disadvantages and where it is used these many questions will raise, So to clarify all these queries we must learn about electric train. For that, this electric train vision is more helpful to clear all queries regarding electric trains.

Locomotives in India consist of electrical and diesel but in this advanced world, we mostly prefer the electrical locomotives because it’s having a more advantage compared to a diesel locomotive.

An electric locomotive is a locomotive powered by electricity from overhead lines, and onboard an energy storage device is placed such as a battery or supercapacitor.

On 3rd of February 1935, the first electric passenger train in India ran between Victoria Terminus (VT) and Kurla Harbour on 1500volts DC overhead traction.

The first electric train was named Deccan Queen and the reason behind this name was, the nickname of Pune is Queen of deccan and this is the first electric train that connects the two largest cities of the Indian state of Maharashtra that is Mumbai and Pune. So this is the reason to keep that particular name to the first electric train.

The Deccan Queen or usually call it as Deccan Queen Express is the first superfast train for the long distances. It is one of India’s first vestibuled trains. This is about the first electric train in India.

View Of Electric Train

Electric Train

This diagram shows an AC electric locomotive. There is a lot of electrical equipment and power electronic devices are used to operate and control the electric locomotive. For every equipment having its own function to operate this whole electric locomotive.

Electric rail engines are generally of 2types, whose traction motor runs with AC and DC. The above red and green lines indicate AC & DC circuits respectively.

Working of electric train

The electric locomotive doesn’t carry fuel or energy source. The energy drives the electric locomotive may be located from 100Km away itself. Electricity produced at the power stations is conveyed to the locomotive through the Catenaries. These catenary lines are placed in parallel to the ground level. A catenary system generally consists of contact wire and droppers.

Contact Wire is a very important element of the electric overhead railway system. It supports the catenary wires and from the contact wire, the pantograph collects the electricity.

The vertical connection between the catenaries and the contact wire is called Droppers and the length of the dropper wire is adjusted so, that the contact wire becomes as horizontal as possible. Earlier dropper wires provided physical support of the contact wire without joining the catenary and contact wires electrically. Modern systems use current-carrying droppers, to eliminating the need for separate wires.

The above three main elements seem like overhead lines at the top of the electric locomotive.

From the contact, wire current is collected by pantograph then-current reaches to circuit breaker from pantograph. These Circuit Breakers are used in case of an emergency or short circuit to stop the current flow.

A Pantograph collects electricity from contact wires. The pantograph is made of carbon strip and it contacts with the overhead wires to collect the electricity. The current collected by pantograph is a single-phase AC of 25000 volts. This high amount of current is not required to run the engine. So, the high amount of electricity transfer to the transformer.

The Transformer sets a huge amount of voltage level into the required voltage level. In most electric locomotives the locomotive sets are powered by Hitachi ABB Power grid transformers and the vast majority of the world’s train manufacturers and train operators having a better trust on them. Hitachi ABB Power grids traction transformers are integral to the capability that means this type of transformers is capable to maintain all the activities in the proper manner.

By using of these advanced transformers the electric locomotive systems improve the performance without fail.

AC current from the transformer is converted into DC by using Rectifier. If the traction motor is DC then it takes the supply from rectifier but nowadays mostly used motors in the electric locomotive are AC traction motors. To drive this motor we need a three-phase AC supply.

The Main and Auxiliary Inverters are used to convert DC into three-phase AC power. This AC supply is given to the traction motor then the motor drives the wheels. To drive the wheels efficiently we use small components like auxiliary inverters and rectifiers.

Transformers and rectifiers produce a lot of heat so, for the cooling purpose, a Cooling Fan is used. A traction motor also produces heat while running of the motor So, for this extra cooling equipments are used and those cooling systems are driven by auxiliary inverters and rectifiers.

A Compressor is used to supply the air at the required pressure to operate a pantograph. It is connected near to the pantograph and it gives the power supply to the pantograph from the batteries.

Electric locomotives in India require an Electric Locomotive Battery to provide startup current. It supplies power to the baby compressor that drives the pantograph. The electric locomotive battery also provides power to the onboard electronics and essential circuits including emergency lighting when the overhead supply fails. The AC electric locomotive battery is designed to meet the tough environments inside the electric locomotive.

In India, an electric locomotive battery is designed for reliable performance, ensures quick recovery from deep discharges, and withstand extreme temperatures, for all this requires a battery manufactured with special lead-tin antimonial alloys.

The electric locomotive batteries and electric multiple units offer 3 of the most important requirements for the railways:

01. They supply power from an offline state, To connect the overhead grid by powering the compressor to activate the pantograph.

02. The electric locomotive battery is designed with simplicity and ease of use. So, it is easy to handle and easy to install.

03. The electric locomotive battery is designed with enough capacity over its lifetime. This ensures operational requirements over trouble-free years of use.

Finally, the choosing of battery is the main thing and it is free from troubleshoots and needs to perform well in the demanding applications.

In the electric locomotive, the motor is used to drive the locomotive and the selection of motor plays a major role in the electrical locomotive.

In olden days the locomotive is driven by DC motors with the low voltage levels up to 1500volts because that time no one knows about AC systems. In the DC motor there are DC commutators due to these commutators there is a problem while starting the locomotive and it is having a low acceleration. So to avoid these situations further this DC system is changed into an AC system.

After a few days, all the people are trying to change the Low voltage DC system into a three-phase AC voltage system with GTO based controlled system to drive the electric locomotive.

But, nowadays a Three-phase AC traction motors with IGBT based controlled system is used to drive the electric locomotive. By using this AC controlled system we have more advantages compared to the DC control system and those advantages are,

  1. Better speed and acceleration control in the engine.
  2. By using this system it provides unity power factor and having fewer harmonics.
  3. Easier to maintain squirrel cage AC induction motor compared to DC motor.
  4. The IGBT based controlled system gives better performance for a given weight and volume.
  5. Better tractive effect and higher adhesion level.
  6. AC motors are lighter than DC motors for the equivalent power.
  7. There is no requirement of brushes in the AC motors. So it’s free from mechanical losses.
  8. By using this system it saves more energy.

Today advanced electric locomotives use Brushless Three Phase Induction Motor. Electric traction allows the use of regenerative braking, due to regenerative braking it feedback the power to the line so by using these motor it saves 40% of the power.

From above we say that there is a lot of elements are working together to drive one electric locomotive. But day by day the technology is improving. In electric locomotive versions also improved from the old version into the new version with good technology.

This is what about the function of each equipment used in the electric locomotive and the total working process of the electric locomotive.

Advantages of electric train

  1. Electric locomotive having more cleanliness compared to diesel engines because it is free from smoke and flue gases.
  2. The electric train having a quick acceleration so there is no loss of time to start.
  3. Lower fuel cost compared to a diesel locomotive.
  4. It is having a capacity to carry large loads.
  5. It requires less maintenance.
  6. In this locomotive, we didn’t use coal so it saves the high-grade coal.
  7. Comfort and Accessibility compared to buses or planes, many trains are downright luxurious.
  8. No noise pollution
  9. Due to regenerative breaking the 40% of electrical energy fed back to the lines so, it saves the electrical energy.
  10. It produces Co2 emissions and those are lighter that means these trains create less wear on tracks.
  11. Easily controllable because electric locomotive consists of so many power electronic devices.
  12. By using of AC traction motors like induction and series motor it is having a high starting torque.

Disadvantages of electric train

  1. High capital cost, because there is more equipment’s, are used to drive the locomotive.
  2. The main drawback of this electric locomotive is, It depends on electricity. If there is any interruption in power supply it went be fail to drive the locomotive.
  3. Lack of control equipment required to drive a single locomotive.

Applications of electric train

  1. Electric locomotive are ideal for commuter rail service with frequent stops.
  2. The electric locomotive used at the high traffic volume routes.
  3. These locomotives are mostly used at the areas which is having an advanced rail network.
  4. It is used to transmit the large loads over a long distances.

Power Consumption In a Year

The Indian railways are one of the largest railway networks in the world with 67,368km of tracks and 22,550 trains, which carry 22.24 million passengers. At present, the railways consume 18.5 billion units of electricity every year. Around 388km of railways were electrified in the country before India gained independence in 1947.

Conclusion

It is observed that the electric train having more facilities with high-quality equipment and it is very essential to train to transfer heavy loads by long distances with super fast speed.

There is no pollution for the environment and it works more efficiently. Every system in the world having advantages and drawbacks. Similarly, electric trains also having drawbacks, those drawbacks are very less but it’s having a lot of advantages.

The major drawback of the electric train is failing of supplying electricity. Whenever it fails to supply the electricity the high-cost equipment is used to recover this problem that’s why the investment cost is high. So from this, one thing we need to understand that By saving electrical energy these all drawbacks will be recovered. Whenever we save the electrical energy then there is no need for extra high-cost equipment then the investment cost also reduced.

In the world, there is a lot of works done by using electrical energy and a lot of importance for electricity production and day by day the demand for electricity is gone be increasing. By saving electrical energy we increase the power production rating. There is a lot of people who are working every day to generate electricity and it’s our time to save energy. Do the right things to save energy it makes a light path for the future.

Save today survive tomorrow

Credit – R Indu

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Chetan Shidling

Automotive | Technical Blogger | Engineer | Content Creator

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